Oracle SQL study plan

Describe the relational model: tables, rows, columns, primary keys, foreign keys, and NULL semantics

Write single-table SELECT statements that project specific columns and use column aliases

Restrict rows using comparison, BETWEEN, IN, LIKE, and NULL-testing predicates

Sort result sets with ORDER BY, including multiple keys and ASC/DESC per column

Predict the exact row order and column headings produced by a given query

Apply character, numeric, and date single-row functions to transform column output

Use NULL-handling functions to substitute values in computed columns

Convert values between character, numeric, and date types with explicit conversion functions

Construct CASE expressions and DECODE-style conditional logic inside a SELECT list

Choose the correct function or conversion when a query must return a specific formatted value

Write inner joins using both explicit JOIN ... ON syntax and implicit WHERE-clause joins

Differentiate equijoins from non-equijoin (range-based) join conditions

Join three or more tables and resolve ambiguous column references with table qualifiers or aliases

Explain how join predicates change row counts compared with single-table retrieval

Write outer joins and identify which side preserves unmatched rows

Self-join a table to compare rows within the same table

Write single-row subqueries in WHERE, HAVING, and SELECT clauses

Distinguish single-row from multi-row subqueries and select the correct comparison operator for each

Debug a join query that returns duplicate or missing rows by inspecting the join condition

Write multi-row subqueries using IN, ANY, and ALL

Use correlated subqueries, including EXISTS and NOT EXISTS, to filter rows against the outer query

Place subqueries in the FROM clause and explain when a scalar subquery is valid in the SELECT list

Apply group functions to summarize rows and state how NULLs affect each function

Form groups with GROUP BY and filter aggregated results with HAVING rather than WHERE

Compose queries that combine GROUP BY, HAVING, and ORDER BY on aggregate results

Detect and fix illegal queries that mix grouped columns with ungrouped ones in the SELECT list

Combine result sets with UNION and UNION ALL and explain the duplicate-handling difference

Use INTERSECT and MINUS to compare two result sets and predict the surviving rows

Verify column count and data type compatibility requirements across set operator operands

Insert rows using explicit column lists, multi-row inserts, and subquery-driven inserts

Update rows with correlated and uncorrelated conditions and predict affected row counts

Delete rows and describe how delete behavior interacts with referential constraints

Perform multi-row DML inside a transaction and use COMMIT and ROLLBACK to control the outcome

Identify which uncommitted changes are visible to the same session versus other sessions

Create and alter tables, including column data types, defaults, and NOT NULL constraints

Create and query views, and describe how a view over a join behaves for DML

Create sequences and synonyms and reference them from DML statements

Describe when an index improves retrieval and when it does not

Complete a full-length timed practice exam and map every missed question back to its domain