200+ Free Oracle SQL Practice Questions

Relational Concepts and Basic SELECT

Study relational database fundamentals, normalization, entity relationship concepts, and the core SELECT statement including aliases, literals, DISTINCT, arithmetic expressions, and DUAL.

Filtering, Sorting, and Substitution Variables

Apply WHERE conditions, operator precedence, ORDER BY rules, pattern matching, NULL checks, and SQL*Plus-style substitution variables.

Single-Row, Conversion, and Conditional Functions

Use character, number, and date functions, nested functions, implicit and explicit conversion, NULL-handling functions, and CASE or DECODE style conditional logic.

Joins and Set Operators

Build inner, outer, self, non-equijoins, and cartesian products, then combine result sets correctly with UNION, UNION ALL, INTERSECT, and MINUS.

Aggregation, Grouping, and Subqueries

Work with group functions, GROUP BY and HAVING, NULL behavior in aggregates, single-row and multiple-row subqueries, correlated subqueries, and EXISTS logic.

DML, MERGE, and Transaction Control

Insert, update, delete, merge, and multitable insert data while understanding COMMIT, ROLLBACK, SAVEPOINT, and transaction visibility.

Tables, Data Types, and Constraints

Create, alter, and drop tables, choose Oracle data types, manage constraints, temporary and external tables, and understand TRUNCATE plus unused-column behavior.

Schema Objects, Privileges, Dictionary, and Time Zones

Review views, indexes, sequences, synonyms, grants and roles, data dictionary views, and date-time topics such as time zone and interval handling.