CREATE TABLE table_203_27 (id NUMBER, "number" NUMBER, "serial no" NUMBER, "entered service" CLOB, "withdrawn" CLOB, "kilometres travelled" NUMBER)

when was number 4102 entered into service ?
SELECT "entered service" FROM table_203_27 WHERE "number" = 4102
SELECT "entered service" FROM "table_203_27" WHERE "number" = 4102