SQL REVIEW

• NULL


  Represents missing or unknown data
• AS


  Alias for columns or tables
• DISTINCT


  Ensure unique values are returned in a SELECT
• LIMIT or TOP


  Limit the number of rows returned in a query
• CAST/CONVERT


  Change the data type of a column or value
• COALESCE


  Return the first non-null value in a list
• TRIGGER


  Define actions to be executed automatically in response to database events
• CREATE INDEX


  Create an index for faster querying
• GRANT


  Used to give specific system privileges to a users
• REVOKE


  Remove privileges granted to other users
• RIGHT JOIN


  Return all rows from the right table and matching rows from the left table
• FULL OUTER JOIN


  Return all rows when there is a match in either table
• UNION


  Combine the results of two or more SELECT statements
• CREATE TABLE


  Create a new table
• ALTER TABLE


  Statement allows you to change column
• DROP TABLE


  Statement allows you to remove tables from your schema
• PRIMARY KEY


  Uniquely identifies each rows in the table
• FOREIGN KEY


  Defines the column in the child table at the table – constraint level
• INDEX


  Create an index for faster data retrieval
• CONSTRAINT


  Enforce rules on columns or tables
• TRUNCATE TABLE


  Remove all data from a table but retain its structure
• COMMIT


  Save changes made in a transaction
• ROLLBACK


  Undo changes made in a transaction
• BEGIN TRANSACTION


  Start a transaction block
• SAVEPOINT


  Create a point within a transaction for later rollback
• EXISTS


  Check if a subquery returns any rows
• CASE


  Perform conditional operations in SQL
• LIKE


  Allows to match similar values, instead of exact values, uses %
• BETWEEN


  Select values within a specified range
• IN


  Filter rows where a column's value matches any value in a list
• SELECT


  Retrieve data from one or more tables
• FROM


  Specify the table(s) from which to retrieve data
• WHERE


  Filter rows based on a specified condition
• INSERT INTO


  Add new records to a table
• VALUES


  Provide the values to be inserted into a table
• UPDATE


  Modify existing records in a table
• SET


  Define the new values for columns when using UPDATE
• DELETE


  Remove records from a table
• DISTINCT


  Retrieve distinct values in a column
• ORDER BY


  Sort the result set based on one or more columns