-- 1. Basic SQL Queries:
SELECT * FROM TableName;
SELECT column1, column2 FROM TableName WHERE condition;
SELECT COUNT(*) FROM TableName;
SELECT DISTINCT column FROM TableName;
SELECT TOP 10 column1 FROM TableName ORDER BY column2 DESC;
-- 2. Joins:
SELECT column1, column2 FROM Table1 INNER JOIN Table2 ON Table1.column = Table2.column;
SELECT column1, column2 FROM Table1 LEFT JOIN Table2 ON Table1.column = Table2.column;
SELECT column1, column2 FROM Table1 RIGHT JOIN Table2 ON Table1.column = Table2.column;
SELECT column1, column2 FROM Table1 FULL OUTER JOIN Table2 ON Table1.column = Table2.column;
-- 3. Aggregations:
SELECT column1, AVG(column2) FROM TableName GROUP BY column1;
SELECT column1, SUM(column2) FROM TableName GROUP BY column1;
SELECT COUNT(DISTINCT column) FROM TableName;
-- 4. Subqueries:
SELECT column FROM TableName WHERE column IN (SELECT column FROM AnotherTable);
-- 5. Constraints and Indexes:
CREATE TABLE TableName (column1 datatype PRIMARY KEY, column2 datatype);
CREATE INDEX index_name ON TableName (column);
-- 6. Performance Tuning:
Analyze table structure, optimize queries, use appropriate indexes, and analyze execution plans.