1. DDL (Data Definition Language)

Keyword	Description
CREATE	Creates a new table, database, index, or view.
ALTER	Modifies an existing database object.
DROP	Deletes an entire table, view, or other object in the database.
TRUNCATE	Removes all records from a table, including all spaces allocated for the records.
RENAME	Renames a database object.
COMMENT	Adds comments to the data dictionary.
COMMENT ON	Provides comments on various database objects.
REPLACE	Replaces an existing object with a new one.

2. DML (Data Manipulation Language)

Keyword	Description
SELECT	Retrieves data from the database.
INSERT	Inserts new data into a table.
UPDATE	Modifies existing data in a table.
DELETE	Removes data from a table.
MERGE	Performs insert, update, or delete operations on a target table based on the results of a join with a source table.
CALL	Executes a stored procedure.
EXPLAIN	Displays the execution plan of a statement.

3. TCL (Transaction Control Language)

Keyword	Description
COMMIT	Saves all changes made in the current transaction.
ROLLBACK	Reverses all changes made in the current transaction.
SAVEPOINT	Sets a point within a transaction to which you can later roll back.
SET TRANSACTION	Specifies characteristics for the current transaction.
BEGIN TRANSACTION	Starts a new transaction.
END TRANSACTION	Ends the current transaction.

4. DCL (Data Control Language)

Keyword	Description
GRANT	Gives users access privileges to the database.
REVOKE	Removes access privileges given by the GRANT command.
DENY	Denies a permission to a principal.

5. DQL (Data Query Language)

Keyword	Description
SELECT	Retrieves data from the database.
FROM	Specifies the table to retrieve data from.
WHERE	Filters records based on a condition.
GROUP BY	Groups rows that have the same values into summary rows.
ORDER BY	Sorts the result-set in ascending or descending order.
HAVING	Filters records that work on summarized GROUP BY results.

6. DTL (Data Transaction Language)

Keyword	Description
BEGIN TRANSACTION	Starts a new transaction.
COMMIT	Saves all changes made in the current transaction.
ROLLBACK	Reverses all changes made in the current transaction.
SAVEPOINT	Sets a point within a transaction to which you can later roll back.
SET TRANSACTION	Specifies characteristics for the current transaction.

7. Others

Keyword	Description
CASE	Creates conditional logic in queries.
COALESCE	Returns the first non-null expression among its arguments.
NULLIF	Returns NULL if the two expressions are equal.
CAST	Converts an expression from one data type to another.
CONVERT	Converts an expression from one data type to another with formatting options.
EXISTS	Checks for the existence of any record in a subquery.
IN	Specifies multiple possible values for a column.
LIKE	Searches for a specified pattern in a column.
BETWEEN	Filters the result set within a certain range.
AND	Combines multiple conditions; all must be true.
OR	Combines multiple conditions; at least one must be true.
NOT	Negates a condition.
AS	Assigns a temporary name to a table or a column for the duration of a query.
NULL	Represents a missing or undefined value.
TOP	Specifies the number of rows to return.
DISTINCT	Removes duplicate records from the result set.
UNION	Combines the result of two or more SELECT statements.
INTERSECT	Returns the common records from two SELECT statements.
MINUS	Returns the records from the first SELECT statement that are not in the second SELECT statement.
OVER	Specifies the window for a window function.
PARTITION BY	Divides the result set into partitions for window functions.
ROW_NUMBER	Assigns a unique sequential integer to rows within a partition of a result set.
RANK	Assigns a rank to each row within a partition of a result set.
DENSE_RANK	Assigns a rank to each row within a partition of a result set without gaps.
NTILE	Divides the result set into a specified number of approximately equal groups.
LEAD	Accesses data from the next row in the result set.
LAG	Accesses data from the previous row in the result set.
FIRST_VALUE	Returns the first value in an ordered set of values.
LAST_VALUE	Returns the last value in an ordered set of values.
COUNT	Returns the number of input rows that match a specific condition of a query.
SUM	Returns the sum of all or distinct values.
AVG	Returns the average value of a numeric column.
MIN	Returns the smallest value of the selected column.
MAX	Returns the largest value of the selected column.
GROUPING SETS	Allows multiple groupings in a single query.
ROLLUP	Creates subtotals that roll up from the most detailed level to a grand total.
CUBE	Creates subtotals for all possible combinations of a set of columns.

Best Practices

• Use uppercase for SQL keywords for better readability.
• Properly format and indent your SQL code.
• Comment your code to explain complex queries.
• Organize keywords into appropriate categories to enhance understanding.
• Avoid using deprecated or obsolete keywords.
• Refer to official documentation for comprehensive keyword usage.

Key Takeaways

• SQL keywords are essential for performing various operations on databases.
• Understanding the categories of SQL keywords helps in writing effective queries.
• Proper usage of keywords ensures efficient and secure database management.
• Familiarity with a wide range of SQL keywords enhances your ability to handle complex database tasks.