CREATE TABLE Maintenance_Contracts (maintenance_contract_id NUMBER, maintenance_contract_company_id NUMBER, contract_start_date DATETIME, contract_end_date DATETIME, other_contract_details VARCHAR2)
CREATE TABLE Skills (skill_id NUMBER, skill_code VARCHAR2, skill_description VARCHAR2)
CREATE TABLE Fault_Log_Parts (fault_log_entry_id NUMBER, part_fault_id NUMBER, fault_status VARCHAR2)
CREATE TABLE Asset_Parts (asset_id NUMBER, part_id NUMBER)
CREATE TABLE Maintenance_Engineers (engineer_id NUMBER, company_id NUMBER, first_name VARCHAR2, last_name VARCHAR2, other_details VARCHAR2)
CREATE TABLE Fault_Log (fault_log_entry_id NUMBER, asset_id NUMBER, recorded_by_staff_id NUMBER, fault_log_entry_datetime DATETIME, fault_description VARCHAR2, other_fault_details VARCHAR2)
CREATE TABLE Engineer_Visits (engineer_visit_id NUMBER, contact_staff_id NUMBER, engineer_id NUMBER, fault_log_entry_id NUMBER, fault_status VARCHAR2, visit_start_datetime DATETIME, visit_end_datetime DATETIME, other_visit_details VARCHAR2)
CREATE TABLE Part_Faults (part_fault_id NUMBER, part_id NUMBER, fault_short_name VARCHAR2, fault_description VARCHAR2, other_fault_details VARCHAR2)
CREATE TABLE Parts (part_id NUMBER, part_name VARCHAR2, chargeable_yn VARCHAR2, chargeable_amount VARCHAR2, other_part_details VARCHAR2)
CREATE TABLE Assets (asset_id NUMBER, maintenance_contract_id NUMBER, supplier_company_id NUMBER, asset_details VARCHAR2, asset_make VARCHAR2, asset_model VARCHAR2, asset_acquired_date DATETIME, asset_disposed_date DATETIME, other_asset_details VARCHAR2)
CREATE TABLE Third_Party_Companies (company_id NUMBER, company_type VARCHAR2, company_name VARCHAR2, company_address VARCHAR2, other_company_details VARCHAR2)
CREATE TABLE Staff (staff_id NUMBER, staff_name VARCHAR2, gender VARCHAR2, other_staff_details VARCHAR2)
CREATE TABLE Engineer_Skills (engineer_id NUMBER, skill_id NUMBER)
CREATE TABLE Skills_Required_To_Fix (part_fault_id NUMBER, skill_id NUMBER)

Return a bar chart on how many engineers did each staff contact? List both the contact staff name and number of engineers contacted.
SELECT staff_name, COUNT(*) FROM Staff AS T1 JOIN Engineer_Visits AS T2 ON T1.staff_id = T2.contact_staff_id GROUP BY T1.staff_name
SELECT "staff_name", COUNT(*) FROM "Staff" "T1" JOIN "Engineer_Visits" "T2" ON "T1"."staff_id" = "T2"."contact_staff_id" GROUP BY "T1"."staff_name"