Client APIs
API Reference Overview
<!-- This section is generated by scripts/generate_c_api_docs.py -->  
#### Open Connect {#docs:api:c:api::open-connect}  
```c
duckdb_state duckdb_open(const char *path, duckdb_database *out_database);
duckdb_state duckdb_open_ext(const char *path, duckdb_database *out_database, duckdb_config config, char **out_error);
void duckdb_close(duckdb_database *database);
duckdb_state duckdb_connect(duckdb_database database, duckdb_connection *out_connection);
void duckdb_interrupt(duckdb_connection connection);
duckdb_query_progress_type duckdb_query_progress(duckdb_connection connection);
void duckdb_disconnect(duckdb_connection *connection);
const char *duckdb_library_version();
```  
#### Configuration {#docs:api:c:api::configuration}  
```c
duckdb_state duckdb_create_config(duckdb_config *out_config);
size_t duckdb_config_count();
duckdb_state duckdb_get_config_flag(size_t index, const char **out_name, const char **out_description);
duckdb_state duckdb_set_config(duckdb_config config, const char *name, const char *option);
void duckdb_destroy_config(duckdb_config *config);
```  
#### Query Execution {#docs:api:c:api::query-execution}  
```c
duckdb_state duckdb_query(duckdb_connection connection, const char *query, duckdb_result *out_result);
void duckdb_destroy_result(duckdb_result *result);
const char *duckdb_column_name(duckdb_result *result, idx_t col);
duckdb_type duckdb_column_type(duckdb_result *result, idx_t col);
duckdb_statement_type duckdb_result_statement_type(duckdb_result result);
duckdb_logical_type duckdb_column_logical_type(duckdb_result *result, idx_t col);
idx_t duckdb_column_count(duckdb_result *result);
idx_t duckdb_row_count(duckdb_result *result);
idx_t duckdb_rows_changed(duckdb_result *result);
void *duckdb_column_data(duckdb_result *result, idx_t col);
bool *duckdb_nullmask_data(duckdb_result *result, idx_t col);
const char *duckdb_result_error(duckdb_result *result);
duckdb_error_type duckdb_result_error_type(duckdb_result *result);
```  
#### Result Functions {#docs:api:c:api::result-functions}  
```c
duckdb_data_chunk duckdb_result_get_chunk(duckdb_result result, idx_t chunk_index);
bool duckdb_result_is_streaming(duckdb_result result);
idx_t duckdb_result_chunk_count(duckdb_result result);
duckdb_result_type duckdb_result_return_type(duckdb_result result);
```  
#### Safe Fetch Functions {#docs:api:c:api::safe-fetch-functions}  
```c
bool duckdb_value_boolean(duckdb_result *result, idx_t col, idx_t row);
int8_t duckdb_value_int8(duckdb_result *result, idx_t col, idx_t row);
int16_t duckdb_value_int16(duckdb_result *result, idx_t col, idx_t row);
int32_t duckdb_value_int32(duckdb_result *result, idx_t col, idx_t row);
int64_t duckdb_value_int64(duckdb_result *result, idx_t col, idx_t row);
duckdb_hugeint duckdb_value_hugeint(duckdb_result *result, idx_t col, idx_t row);
duckdb_uhugeint duckdb_value_uhugeint(duckdb_result *result, idx_t col, idx_t row);
duckdb_decimal duckdb_value_decimal(duckdb_result *result, idx_t col, idx_t row);
uint8_t duckdb_value_uint8(duckdb_result *result, idx_t col, idx_t row);
uint16_t duckdb_value_uint16(duckdb_result *result, idx_t col, idx_t row);
uint32_t duckdb_value_uint32(duckdb_result *result, idx_t col, idx_t row);
uint64_t duckdb_value_uint64(duckdb_result *result, idx_t col, idx_t row);
float duckdb_value_float(duckdb_result *result, idx_t col, idx_t row);
double duckdb_value_double(duckdb_result *result, idx_t col, idx_t row);
duckdb_date duckdb_value_date(duckdb_result *result, idx_t col, idx_t row);
duckdb_time duckdb_value_time(duckdb_result *result, idx_t col, idx_t row);
duckdb_timestamp duckdb_value_timestamp(duckdb_result *result, idx_t col, idx_t row);
duckdb_interval duckdb_value_interval(duckdb_result *result, idx_t col, idx_t row);
char *duckdb_value_varchar(duckdb_result *result, idx_t col, idx_t row);
duckdb_string duckdb_value_string(duckdb_result *result, idx_t col, idx_t row);
char *duckdb_value_varchar_internal(duckdb_result *result, idx_t col, idx_t row);
duckdb_string duckdb_value_string_internal(duckdb_result *result, idx_t col, idx_t row);
duckdb_blob duckdb_value_blob(duckdb_result *result, idx_t col, idx_t row);
bool duckdb_value_is_null(duckdb_result *result, idx_t col, idx_t row);
```  
#### Helpers {#docs:api:c:api::helpers}  
```c
void *duckdb_malloc(size_t size);
void duckdb_free(void *ptr);
idx_t duckdb_vector_size();
bool duckdb_string_is_inlined(duckdb_string_t string);
uint32_t duckdb_string_t_length(duckdb_string_t string);
const char *duckdb_string_t_data(duckdb_string_t *string);
```  
#### Date Time Timestamp Helpers {#docs:api:c:api::date-time-timestamp-helpers}  
```c
duckdb_date_struct duckdb_from_date(duckdb_date date);
duckdb_date duckdb_to_date(duckdb_date_struct date);
bool duckdb_is_finite_date(duckdb_date date);
duckdb_time_struct duckdb_from_time(duckdb_time time);
duckdb_time_tz duckdb_create_time_tz(int64_t micros, int32_t offset);
duckdb_time_tz_struct duckdb_from_time_tz(duckdb_time_tz micros);
duckdb_time duckdb_to_time(duckdb_time_struct time);
duckdb_timestamp_struct duckdb_from_timestamp(duckdb_timestamp ts);
duckdb_timestamp duckdb_to_timestamp(duckdb_timestamp_struct ts);
bool duckdb_is_finite_timestamp(duckdb_timestamp ts);
```  
#### Hugeint Helpers {#docs:api:c:api::hugeint-helpers}  
```c
double duckdb_hugeint_to_double(duckdb_hugeint val);
duckdb_hugeint duckdb_double_to_hugeint(double val);
```  
#### Unsigned Hugeint Helpers {#docs:api:c:api::unsigned-hugeint-helpers}  
```c
double duckdb_uhugeint_to_double(duckdb_uhugeint val);
duckdb_uhugeint duckdb_double_to_uhugeint(double val);
```  
#### Decimal Helpers {#docs:api:c:api::decimal-helpers}  
```c
duckdb_decimal duckdb_double_to_decimal(double val, uint8_t width, uint8_t scale);
double duckdb_decimal_to_double(duckdb_decimal val);
```  
#### Prepared Statements {#docs:api:c:api::prepared-statements}  
```c
duckdb_state duckdb_prepare(duckdb_connection connection, const char *query, duckdb_prepared_statement *out_prepared_statement);
void duckdb_destroy_prepare(duckdb_prepared_statement *prepared_statement);
const char *duckdb_prepare_error(duckdb_prepared_statement prepared_statement);
idx_t duckdb_nparams(duckdb_prepared_statement prepared_statement);
const char *duckdb_parameter_name(duckdb_prepared_statement prepared_statement, idx_t index);
duckdb_type duckdb_param_type(duckdb_prepared_statement prepared_statement, idx_t param_idx);
duckdb_state duckdb_clear_bindings(duckdb_prepared_statement prepared_statement);
duckdb_statement_type duckdb_prepared_statement_type(duckdb_prepared_statement statement);
```  
#### Bind Values To Prepared Statements {#docs:api:c:api::bind-values-to-prepared-statements}  
```c
duckdb_state duckdb_bind_value(duckdb_prepared_statement prepared_statement, idx_t param_idx, duckdb_value val);
duckdb_state duckdb_bind_parameter_index(duckdb_prepared_statement prepared_statement, idx_t *param_idx_out, const char *name);
duckdb_state duckdb_bind_boolean(duckdb_prepared_statement prepared_statement, idx_t param_idx, bool val);
duckdb_state duckdb_bind_int8(duckdb_prepared_statement prepared_statement, idx_t param_idx, int8_t val);
duckdb_state duckdb_bind_int16(duckdb_prepared_statement prepared_statement, idx_t param_idx, int16_t val);
duckdb_state duckdb_bind_int32(duckdb_prepared_statement prepared_statement, idx_t param_idx, int32_t val);
duckdb_state duckdb_bind_int64(duckdb_prepared_statement prepared_statement, idx_t param_idx, int64_t val);
duckdb_state duckdb_bind_hugeint(duckdb_prepared_statement prepared_statement, idx_t param_idx, duckdb_hugeint val);
duckdb_state duckdb_bind_uhugeint(duckdb_prepared_statement prepared_statement, idx_t param_idx, duckdb_uhugeint val);
duckdb_state duckdb_bind_decimal(duckdb_prepared_statement prepared_statement, idx_t param_idx, duckdb_decimal val);
duckdb_state duckdb_bind_uint8(duckdb_prepared_statement prepared_statement, idx_t param_idx, uint8_t val);
duckdb_state duckdb_bind_uint16(duckdb_prepared_statement prepared_statement, idx_t param_idx, uint16_t val);
duckdb_state duckdb_bind_uint32(duckdb_prepared_statement prepared_statement, idx_t param_idx, uint32_t val);
duckdb_state duckdb_bind_uint64(duckdb_prepared_statement prepared_statement, idx_t param_idx, uint64_t val);
duckdb_state duckdb_bind_float(duckdb_prepared_statement prepared_statement, idx_t param_idx, float val);
duckdb_state duckdb_bind_double(duckdb_prepared_statement prepared_statement, idx_t param_idx, double val);
duckdb_state duckdb_bind_date(duckdb_prepared_statement prepared_statement, idx_t param_idx, duckdb_date val);
duckdb_state duckdb_bind_time(duckdb_prepared_statement prepared_statement, idx_t param_idx, duckdb_time val);
duckdb_state duckdb_bind_timestamp(duckdb_prepared_statement prepared_statement, idx_t param_idx, duckdb_timestamp val);
duckdb_state duckdb_bind_timestamp_tz(duckdb_prepared_statement prepared_statement, idx_t param_idx, duckdb_timestamp val);
duckdb_state duckdb_bind_interval(duckdb_prepared_statement prepared_statement, idx_t param_idx, duckdb_interval val);
duckdb_state duckdb_bind_varchar(duckdb_prepared_statement prepared_statement, idx_t param_idx, const char *val);
duckdb_state duckdb_bind_varchar_length(duckdb_prepared_statement prepared_statement, idx_t param_idx, const char *val, idx_t length);
duckdb_state duckdb_bind_blob(duckdb_prepared_statement prepared_statement, idx_t param_idx, const void *data, idx_t length);
duckdb_state duckdb_bind_null(duckdb_prepared_statement prepared_statement, idx_t param_idx);
```  
#### Execute Prepared Statements {#docs:api:c:api::execute-prepared-statements}  
```c
duckdb_state duckdb_execute_prepared(duckdb_prepared_statement prepared_statement, duckdb_result *out_result);
duckdb_state duckdb_execute_prepared_streaming(duckdb_prepared_statement prepared_statement, duckdb_result *out_result);
```  
#### Extract Statements {#docs:api:c:api::extract-statements}  
```c
idx_t duckdb_extract_statements(duckdb_connection connection, const char *query, duckdb_extracted_statements *out_extracted_statements);
duckdb_state duckdb_prepare_extracted_statement(duckdb_connection connection, duckdb_extracted_statements extracted_statements, idx_t index, duckdb_prepared_statement *out_prepared_statement);
const char *duckdb_extract_statements_error(duckdb_extracted_statements extracted_statements);
void duckdb_destroy_extracted(duckdb_extracted_statements *extracted_statements);
```  
#### Pending Result Interface {#docs:api:c:api::pending-result-interface}  
```c
duckdb_state duckdb_pending_prepared(duckdb_prepared_statement prepared_statement, duckdb_pending_result *out_result);
duckdb_state duckdb_pending_prepared_streaming(duckdb_prepared_statement prepared_statement, duckdb_pending_result *out_result);
void duckdb_destroy_pending(duckdb_pending_result *pending_result);
const char *duckdb_pending_error(duckdb_pending_result pending_result);
duckdb_pending_state duckdb_pending_execute_task(duckdb_pending_result pending_result);
duckdb_pending_state duckdb_pending_execute_check_state(duckdb_pending_result pending_result);
duckdb_state duckdb_execute_pending(duckdb_pending_result pending_result, duckdb_result *out_result);
bool duckdb_pending_execution_is_finished(duckdb_pending_state pending_state);
```  
#### Value Interface {#docs:api:c:api::value-interface}  
```c
void duckdb_destroy_value(duckdb_value *value);
duckdb_value duckdb_create_varchar(const char *text);
duckdb_value duckdb_create_varchar_length(const char *text, idx_t length);
duckdb_value duckdb_create_bool(bool input);
duckdb_value duckdb_create_int8(int8_t input);
duckdb_value duckdb_create_uint8(uint8_t input);
duckdb_value duckdb_create_int16(int16_t input);
duckdb_value duckdb_create_uint16(uint16_t input);
duckdb_value duckdb_create_int32(int32_t input);
duckdb_value duckdb_create_uint32(uint32_t input);
duckdb_value duckdb_create_uint64(uint64_t input);
duckdb_value duckdb_create_int64(int64_t val);
duckdb_value duckdb_create_hugeint(duckdb_hugeint input);
duckdb_value duckdb_create_uhugeint(duckdb_uhugeint input);
duckdb_value duckdb_create_float(float input);
duckdb_value duckdb_create_double(double input);
duckdb_value duckdb_create_date(duckdb_date input);
duckdb_value duckdb_create_time(duckdb_time input);
duckdb_value duckdb_create_time_tz_value(duckdb_time_tz value);
duckdb_value duckdb_create_timestamp(duckdb_timestamp input);
duckdb_value duckdb_create_interval(duckdb_interval input);
duckdb_value duckdb_create_blob(const uint8_t *data, idx_t length);
bool duckdb_get_bool(duckdb_value val);
int8_t duckdb_get_int8(duckdb_value val);
uint8_t duckdb_get_uint8(duckdb_value val);
int16_t duckdb_get_int16(duckdb_value val);
uint16_t duckdb_get_uint16(duckdb_value val);
int32_t duckdb_get_int32(duckdb_value val);
uint32_t duckdb_get_uint32(duckdb_value val);
int64_t duckdb_get_int64(duckdb_value val);
uint64_t duckdb_get_uint64(duckdb_value val);
duckdb_hugeint duckdb_get_hugeint(duckdb_value val);
duckdb_uhugeint duckdb_get_uhugeint(duckdb_value val);
float duckdb_get_float(duckdb_value val);
double duckdb_get_double(duckdb_value val);
duckdb_date duckdb_get_date(duckdb_value val);
duckdb_time duckdb_get_time(duckdb_value val);
duckdb_time_tz duckdb_get_time_tz(duckdb_value val);
duckdb_timestamp duckdb_get_timestamp(duckdb_value val);
duckdb_interval duckdb_get_interval(duckdb_value val);
duckdb_logical_type duckdb_get_value_type(duckdb_value val);
duckdb_blob duckdb_get_blob(duckdb_value val);
char *duckdb_get_varchar(duckdb_value value);
duckdb_value duckdb_create_struct_value(duckdb_logical_type type, duckdb_value *values);
duckdb_value duckdb_create_list_value(duckdb_logical_type type, duckdb_value *values, idx_t value_count);
duckdb_value duckdb_create_array_value(duckdb_logical_type type, duckdb_value *values, idx_t value_count);
idx_t duckdb_get_map_size(duckdb_value value);
duckdb_value duckdb_get_map_key(duckdb_value value, idx_t index);
duckdb_value duckdb_get_map_value(duckdb_value value, idx_t index);
```  
#### Logical Type Interface {#docs:api:c:api::logical-type-interface}  
```c
duckdb_logical_type duckdb_create_logical_type(duckdb_type type);
char *duckdb_logical_type_get_alias(duckdb_logical_type type);
void duckdb_logical_type_set_alias(duckdb_logical_type type, const char *alias);
duckdb_logical_type duckdb_create_list_type(duckdb_logical_type type);
duckdb_logical_type duckdb_create_array_type(duckdb_logical_type type, idx_t array_size);
duckdb_logical_type duckdb_create_map_type(duckdb_logical_type key_type, duckdb_logical_type value_type);
duckdb_logical_type duckdb_create_union_type(duckdb_logical_type *member_types, const char **member_names, idx_t member_count);
duckdb_logical_type duckdb_create_struct_type(duckdb_logical_type *member_types, const char **member_names, idx_t member_count);
duckdb_logical_type duckdb_create_enum_type(const char **member_names, idx_t member_count);
duckdb_logical_type duckdb_create_decimal_type(uint8_t width, uint8_t scale);
duckdb_type duckdb_get_type_id(duckdb_logical_type type);
uint8_t duckdb_decimal_width(duckdb_logical_type type);
uint8_t duckdb_decimal_scale(duckdb_logical_type type);
duckdb_type duckdb_decimal_internal_type(duckdb_logical_type type);
duckdb_type duckdb_enum_internal_type(duckdb_logical_type type);
uint32_t duckdb_enum_dictionary_size(duckdb_logical_type type);
char *duckdb_enum_dictionary_value(duckdb_logical_type type, idx_t index);
duckdb_logical_type duckdb_list_type_child_type(duckdb_logical_type type);
duckdb_logical_type duckdb_array_type_child_type(duckdb_logical_type type);
idx_t duckdb_array_type_array_size(duckdb_logical_type type);
duckdb_logical_type duckdb_map_type_key_type(duckdb_logical_type type);
duckdb_logical_type duckdb_map_type_value_type(duckdb_logical_type type);
idx_t duckdb_struct_type_child_count(duckdb_logical_type type);
char *duckdb_struct_type_child_name(duckdb_logical_type type, idx_t index);
duckdb_logical_type duckdb_struct_type_child_type(duckdb_logical_type type, idx_t index);
idx_t duckdb_union_type_member_count(duckdb_logical_type type);
char *duckdb_union_type_member_name(duckdb_logical_type type, idx_t index);
duckdb_logical_type duckdb_union_type_member_type(duckdb_logical_type type, idx_t index);
void duckdb_destroy_logical_type(duckdb_logical_type *type);
duckdb_state duckdb_register_logical_type(duckdb_connection con, duckdb_logical_type type, duckdb_create_type_info info);
```  
#### Data Chunk Interface {#docs:api:c:api::data-chunk-interface}  
```c
duckdb_data_chunk duckdb_create_data_chunk(duckdb_logical_type *types, idx_t column_count);
void duckdb_destroy_data_chunk(duckdb_data_chunk *chunk);
void duckdb_data_chunk_reset(duckdb_data_chunk chunk);
idx_t duckdb_data_chunk_get_column_count(duckdb_data_chunk chunk);
duckdb_vector duckdb_data_chunk_get_vector(duckdb_data_chunk chunk, idx_t col_idx);
idx_t duckdb_data_chunk_get_size(duckdb_data_chunk chunk);
void duckdb_data_chunk_set_size(duckdb_data_chunk chunk, idx_t size);
```  
#### Vector Interface {#docs:api:c:api::vector-interface}  
```c
duckdb_logical_type duckdb_vector_get_column_type(duckdb_vector vector);
void *duckdb_vector_get_data(duckdb_vector vector);
uint64_t *duckdb_vector_get_validity(duckdb_vector vector);
void duckdb_vector_ensure_validity_writable(duckdb_vector vector);
void duckdb_vector_assign_string_element(duckdb_vector vector, idx_t index, const char *str);
void duckdb_vector_assign_string_element_len(duckdb_vector vector, idx_t index, const char *str, idx_t str_len);
duckdb_vector duckdb_list_vector_get_child(duckdb_vector vector);
idx_t duckdb_list_vector_get_size(duckdb_vector vector);
duckdb_state duckdb_list_vector_set_size(duckdb_vector vector, idx_t size);
duckdb_state duckdb_list_vector_reserve(duckdb_vector vector, idx_t required_capacity);
duckdb_vector duckdb_struct_vector_get_child(duckdb_vector vector, idx_t index);
duckdb_vector duckdb_array_vector_get_child(duckdb_vector vector);
```  
#### Validity Mask Functions {#docs:api:c:api::validity-mask-functions}  
```c
bool duckdb_validity_row_is_valid(uint64_t *validity, idx_t row);
void duckdb_validity_set_row_validity(uint64_t *validity, idx_t row, bool valid);
void duckdb_validity_set_row_invalid(uint64_t *validity, idx_t row);
void duckdb_validity_set_row_valid(uint64_t *validity, idx_t row);
```  
#### Scalar Functions {#docs:api:c:api::scalar-functions}  
```c
duckdb_scalar_function duckdb_create_scalar_function();
void duckdb_destroy_scalar_function(duckdb_scalar_function *scalar_function);
void duckdb_scalar_function_set_name(duckdb_scalar_function scalar_function, const char *name);
void duckdb_scalar_function_set_varargs(duckdb_scalar_function scalar_function, duckdb_logical_type type);
void duckdb_scalar_function_set_special_handling(duckdb_scalar_function scalar_function);
void duckdb_scalar_function_set_volatile(duckdb_scalar_function scalar_function);
void duckdb_scalar_function_add_parameter(duckdb_scalar_function scalar_function, duckdb_logical_type type);
void duckdb_scalar_function_set_return_type(duckdb_scalar_function scalar_function, duckdb_logical_type type);
void duckdb_scalar_function_set_extra_info(duckdb_scalar_function scalar_function, void *extra_info, duckdb_delete_callback_t destroy);
void duckdb_scalar_function_set_function(duckdb_scalar_function scalar_function, duckdb_scalar_function_t function);
duckdb_state duckdb_register_scalar_function(duckdb_connection con, duckdb_scalar_function scalar_function);
void *duckdb_scalar_function_get_extra_info(duckdb_function_info info);
void duckdb_scalar_function_set_error(duckdb_function_info info, const char *error);
duckdb_scalar_function_set duckdb_create_scalar_function_set(const char *name);
void duckdb_destroy_scalar_function_set(duckdb_scalar_function_set *scalar_function_set);
duckdb_state duckdb_add_scalar_function_to_set(duckdb_scalar_function_set set, duckdb_scalar_function function);
duckdb_state duckdb_register_scalar_function_set(duckdb_connection con, duckdb_scalar_function_set set);
```  
#### Aggregate Functions {#docs:api:c:api::aggregate-functions}  
```c
duckdb_aggregate_function duckdb_create_aggregate_function();
void duckdb_destroy_aggregate_function(duckdb_aggregate_function *aggregate_function);
void duckdb_aggregate_function_set_name(duckdb_aggregate_function aggregate_function, const char *name);
void duckdb_aggregate_function_add_parameter(duckdb_aggregate_function aggregate_function, duckdb_logical_type type);
void duckdb_aggregate_function_set_return_type(duckdb_aggregate_function aggregate_function, duckdb_logical_type type);
void duckdb_aggregate_function_set_functions(duckdb_aggregate_function aggregate_function, duckdb_aggregate_state_size state_size, duckdb_aggregate_init_t state_init, duckdb_aggregate_update_t update, duckdb_aggregate_combine_t combine, duckdb_aggregate_finalize_t finalize);
void duckdb_aggregate_function_set_destructor(duckdb_aggregate_function aggregate_function, duckdb_aggregate_destroy_t destroy);
duckdb_state duckdb_register_aggregate_function(duckdb_connection con, duckdb_aggregate_function aggregate_function);
void duckdb_aggregate_function_set_special_handling(duckdb_aggregate_function aggregate_function);
void duckdb_aggregate_function_set_extra_info(duckdb_aggregate_function aggregate_function, void *extra_info, duckdb_delete_callback_t destroy);
void *duckdb_aggregate_function_get_extra_info(duckdb_function_info info);
void duckdb_aggregate_function_set_error(duckdb_function_info info, const char *error);
duckdb_aggregate_function_set duckdb_create_aggregate_function_set(const char *name);
void duckdb_destroy_aggregate_function_set(duckdb_aggregate_function_set *aggregate_function_set);
duckdb_state duckdb_add_aggregate_function_to_set(duckdb_aggregate_function_set set, duckdb_aggregate_function function);
duckdb_state duckdb_register_aggregate_function_set(duckdb_connection con, duckdb_aggregate_function_set set);
```  
#### Table Functions {#docs:api:c:api::table-functions}  
```c
duckdb_table_function duckdb_create_table_function();
void duckdb_destroy_table_function(duckdb_table_function *table_function);
void duckdb_table_function_set_name(duckdb_table_function table_function, const char *name);
void duckdb_table_function_add_parameter(duckdb_table_function table_function, duckdb_logical_type type);
void duckdb_table_function_add_named_parameter(duckdb_table_function table_function, const char *name, duckdb_logical_type type);
void duckdb_table_function_set_extra_info(duckdb_table_function table_function, void *extra_info, duckdb_delete_callback_t destroy);
void duckdb_table_function_set_bind(duckdb_table_function table_function, duckdb_table_function_bind_t bind);
void duckdb_table_function_set_init(duckdb_table_function table_function, duckdb_table_function_init_t init);
void duckdb_table_function_set_local_init(duckdb_table_function table_function, duckdb_table_function_init_t init);
void duckdb_table_function_set_function(duckdb_table_function table_function, duckdb_table_function_t function);
void duckdb_table_function_supports_projection_pushdown(duckdb_table_function table_function, bool pushdown);
duckdb_state duckdb_register_table_function(duckdb_connection con, duckdb_table_function function);
```  
#### Table Function Bind {#docs:api:c:api::table-function-bind}  
```c
void *duckdb_bind_get_extra_info(duckdb_bind_info info);
void duckdb_bind_add_result_column(duckdb_bind_info info, const char *name, duckdb_logical_type type);
idx_t duckdb_bind_get_parameter_count(duckdb_bind_info info);
duckdb_value duckdb_bind_get_parameter(duckdb_bind_info info, idx_t index);
duckdb_value duckdb_bind_get_named_parameter(duckdb_bind_info info, const char *name);
void duckdb_bind_set_bind_data(duckdb_bind_info info, void *bind_data, duckdb_delete_callback_t destroy);
void duckdb_bind_set_cardinality(duckdb_bind_info info, idx_t cardinality, bool is_exact);
void duckdb_bind_set_error(duckdb_bind_info info, const char *error);
```  
#### Table Function Init {#docs:api:c:api::table-function-init}  
```c
void *duckdb_init_get_extra_info(duckdb_init_info info);
void *duckdb_init_get_bind_data(duckdb_init_info info);
void duckdb_init_set_init_data(duckdb_init_info info, void *init_data, duckdb_delete_callback_t destroy);
idx_t duckdb_init_get_column_count(duckdb_init_info info);
idx_t duckdb_init_get_column_index(duckdb_init_info info, idx_t column_index);
void duckdb_init_set_max_threads(duckdb_init_info info, idx_t max_threads);
void duckdb_init_set_error(duckdb_init_info info, const char *error);
```  
#### Table Function {#docs:api:c:api::table-function}  
```c
void *duckdb_function_get_extra_info(duckdb_function_info info);
void *duckdb_function_get_bind_data(duckdb_function_info info);
void *duckdb_function_get_init_data(duckdb_function_info info);
void *duckdb_function_get_local_init_data(duckdb_function_info info);
void duckdb_function_set_error(duckdb_function_info info, const char *error);
```  
#### Replacement Scans {#docs:api:c:api::replacement-scans}  
```c
void duckdb_add_replacement_scan(duckdb_database db, duckdb_replacement_callback_t replacement, void *extra_data, duckdb_delete_callback_t delete_callback);
void duckdb_replacement_scan_set_function_name(duckdb_replacement_scan_info info, const char *function_name);
void duckdb_replacement_scan_add_parameter(duckdb_replacement_scan_info info, duckdb_value parameter);
void duckdb_replacement_scan_set_error(duckdb_replacement_scan_info info, const char *error);
```  
#### Profiling Info {#docs:api:c:api::profiling-info}  
```c
duckdb_profiling_info duckdb_get_profiling_info(duckdb_connection connection);
duckdb_value duckdb_profiling_info_get_value(duckdb_profiling_info info, const char *key);
duckdb_value duckdb_profiling_info_get_metrics(duckdb_profiling_info info);
idx_t duckdb_profiling_info_get_child_count(duckdb_profiling_info info);
duckdb_profiling_info duckdb_profiling_info_get_child(duckdb_profiling_info info, idx_t index);
```  
#### Appender {#docs:api:c:api::appender}  
```c
duckdb_state duckdb_appender_create(duckdb_connection connection, const char *schema, const char *table, duckdb_appender *out_appender);
idx_t duckdb_appender_column_count(duckdb_appender appender);
duckdb_logical_type duckdb_appender_column_type(duckdb_appender appender, idx_t col_idx);
const char *duckdb_appender_error(duckdb_appender appender);
duckdb_state duckdb_appender_flush(duckdb_appender appender);
duckdb_state duckdb_appender_close(duckdb_appender appender);
duckdb_state duckdb_appender_destroy(duckdb_appender *appender);
duckdb_state duckdb_appender_begin_row(duckdb_appender appender);
duckdb_state duckdb_appender_end_row(duckdb_appender appender);
duckdb_state duckdb_append_default(duckdb_appender appender);
duckdb_state duckdb_append_bool(duckdb_appender appender, bool value);
duckdb_state duckdb_append_int8(duckdb_appender appender, int8_t value);
duckdb_state duckdb_append_int16(duckdb_appender appender, int16_t value);
duckdb_state duckdb_append_int32(duckdb_appender appender, int32_t value);
duckdb_state duckdb_append_int64(duckdb_appender appender, int64_t value);
duckdb_state duckdb_append_hugeint(duckdb_appender appender, duckdb_hugeint value);
duckdb_state duckdb_append_uint8(duckdb_appender appender, uint8_t value);
duckdb_state duckdb_append_uint16(duckdb_appender appender, uint16_t value);
duckdb_state duckdb_append_uint32(duckdb_appender appender, uint32_t value);
duckdb_state duckdb_append_uint64(duckdb_appender appender, uint64_t value);
duckdb_state duckdb_append_uhugeint(duckdb_appender appender, duckdb_uhugeint value);
duckdb_state duckdb_append_float(duckdb_appender appender, float value);
duckdb_state duckdb_append_double(duckdb_appender appender, double value);
duckdb_state duckdb_append_date(duckdb_appender appender, duckdb_date value);
duckdb_state duckdb_append_time(duckdb_appender appender, duckdb_time value);
duckdb_state duckdb_append_timestamp(duckdb_appender appender, duckdb_timestamp value);
duckdb_state duckdb_append_interval(duckdb_appender appender, duckdb_interval value);
duckdb_state duckdb_append_varchar(duckdb_appender appender, const char *val);
duckdb_state duckdb_append_varchar_length(duckdb_appender appender, const char *val, idx_t length);
duckdb_state duckdb_append_blob(duckdb_appender appender, const void *data, idx_t length);
duckdb_state duckdb_append_null(duckdb_appender appender);
duckdb_state duckdb_append_data_chunk(duckdb_appender appender, duckdb_data_chunk chunk);
```  
#### Table Description {#docs:api:c:api::table-description}  
```c
duckdb_state duckdb_table_description_create(duckdb_connection connection, const char *schema, const char *table, duckdb_table_description *out);
void duckdb_table_description_destroy(duckdb_table_description *table_description);
const char *duckdb_table_description_error(duckdb_table_description table_description);
duckdb_state duckdb_column_has_default(duckdb_table_description table_description, idx_t index, bool *out);
```  
#### Arrow Interface {#docs:api:c:api::arrow-interface}  
```c
duckdb_state duckdb_query_arrow(duckdb_connection connection, const char *query, duckdb_arrow *out_result);
duckdb_state duckdb_query_arrow_schema(duckdb_arrow result, duckdb_arrow_schema *out_schema);
duckdb_state duckdb_prepared_arrow_schema(duckdb_prepared_statement prepared, duckdb_arrow_schema *out_schema);
void duckdb_result_arrow_array(duckdb_result result, duckdb_data_chunk chunk, duckdb_arrow_array *out_array);
duckdb_state duckdb_query_arrow_array(duckdb_arrow result, duckdb_arrow_array *out_array);
idx_t duckdb_arrow_column_count(duckdb_arrow result);
idx_t duckdb_arrow_row_count(duckdb_arrow result);
idx_t duckdb_arrow_rows_changed(duckdb_arrow result);
const char *duckdb_query_arrow_error(duckdb_arrow result);
void duckdb_destroy_arrow(duckdb_arrow *result);
void duckdb_destroy_arrow_stream(duckdb_arrow_stream *stream_p);
duckdb_state duckdb_execute_prepared_arrow(duckdb_prepared_statement prepared_statement, duckdb_arrow *out_result);
duckdb_state duckdb_arrow_scan(duckdb_connection connection, const char *table_name, duckdb_arrow_stream arrow);
duckdb_state duckdb_arrow_array_scan(duckdb_connection connection, const char *table_name, duckdb_arrow_schema arrow_schema, duckdb_arrow_array arrow_array, duckdb_arrow_stream *out_stream);
```  
#### Threading Information {#docs:api:c:api::threading-information}  
```c
void duckdb_execute_tasks(duckdb_database database, idx_t max_tasks);
duckdb_task_state duckdb_create_task_state(duckdb_database database);
void duckdb_execute_tasks_state(duckdb_task_state state);
idx_t duckdb_execute_n_tasks_state(duckdb_task_state state, idx_t max_tasks);
void duckdb_finish_execution(duckdb_task_state state);
bool duckdb_task_state_is_finished(duckdb_task_state state);
void duckdb_destroy_task_state(duckdb_task_state state);
bool duckdb_execution_is_finished(duckdb_connection con);
```  
#### Streaming Result Interface {#docs:api:c:api::streaming-result-interface}  
```c
duckdb_data_chunk duckdb_stream_fetch_chunk(duckdb_result result);
duckdb_data_chunk duckdb_fetch_chunk(duckdb_result result);
```  
#### Cast Functions {#docs:api:c:api::cast-functions}  
```c
duckdb_cast_function duckdb_create_cast_function();
void duckdb_cast_function_set_source_type(duckdb_cast_function cast_function, duckdb_logical_type source_type);
void duckdb_cast_function_set_target_type(duckdb_cast_function cast_function, duckdb_logical_type target_type);
void duckdb_cast_function_set_implicit_cast_cost(duckdb_cast_function cast_function, int64_t cost);
void duckdb_cast_function_set_function(duckdb_cast_function cast_function, duckdb_cast_function_t function);
void duckdb_cast_function_set_extra_info(duckdb_cast_function cast_function, void *extra_info, duckdb_delete_callback_t destroy);
void *duckdb_cast_function_get_extra_info(duckdb_function_info info);
duckdb_cast_mode duckdb_cast_function_get_cast_mode(duckdb_function_info info);
void duckdb_cast_function_set_error(duckdb_function_info info, const char *error);
void duckdb_cast_function_set_row_error(duckdb_function_info info, const char *error, idx_t row, duckdb_vector output);
duckdb_state duckdb_register_cast_function(duckdb_connection con, duckdb_cast_function cast_function);
void duckdb_destroy_cast_function(duckdb_cast_function *cast_function);
```