SQL Reference

Quick Reference

This is a quick reference list of SQL keywords and how they are used to write SQL statements.

  • SQL – ADD Keyword
    The ADD keyword is used to add columns or constraints to an existing table.
  • SQL – ALL Keyword
    The ALL keyword returns true if all of the subquery conditions are met.
  • SQL – ALTER Keyword
    The ALTER keyword adds, deletes, or modifies columns in a table. It can also add and delete various constraints in a table.
  • SQL – AND Keyword
    The AND keyword is used with the WHERE keyword to only include rows where both conditions is true.
  • SQL – ANY Keyword
    The ANY keyword returns true if any of the subquery conditions are met.
  • SQL – AS Keyword
    The AS keyword is used to output a column or table with a temporary alias for the duration of the query. Nothing in the database itself is altered.
  • SQL – ASC Keyword
    The ASC keyword is used to sort the returned data in ascending order (A – Z).
  • SQL – BACKUP DATABASE Keywords
    The BACKUP DATABASE keywords are used in SQL Server to create a full back up of an existing SQL database.
  • SQL – BETWEEN Keyword
    The BETWEEN keyword is used to select values (numbers, text, or dates) within a given range (inclusively).
  • SQL – CASE Keyword
    The CASE keyword is used is to create different output based on various conditions.
  • SQL – CHECK Keyword
    The CHECK keyword is a constraint that limits the value that can be placed in a column.
  • SQL – COLUMN Keyword
    The COLUMN keyword is used to change the data type of a column or delete a column in a table.
  • SQL – CONSTRAINT Keyword
    The CONSTRAINT keyword is used to create or delete a constraint from an existing table.
  • SQL – CREATE Keyword
    The CREATE keyword is used to create new databases, indexes, procedures, tables, and views.
  • SQL – DATABASE Keyword
    The DATABASE keyword is used to create a new SQL database or delete an existing SQL database.
  • SQL – DEFAULT Keyword
    The DEFAULT keyword provides a default value for a column that will be added to all new records if no other value is specified.
  • SQL – DELETE Keyword
    The DELETE keyword is used to delete existing records in a table.
  • SQL – DESC Keyword
    The DESC keyword is used to sort the returned data in descending order (Z – A).
  • SQL – DISTINCT Keyword
    The DISTINCT keyword returns only different values (no two values the same) in the result set.
  • SQL – DROP Keyword
    The DROP keyword is used to delete existing columns, constraints, databases, indexes, tables, and views.
  • SQL – EXEC Keyword
    The EXEC keyword is used to execute a stored procedure.
  • SQL – EXISTS Keyword
    The EXISTS keyword tests for the existence of any record in a subquery, and returns “true” if the subquery returns one or more records.
  • SQL – FOREIGN KEY Keywords
    The FOREIGN KEY keywords are a key (a field or fields in one table that refers to the PRIMARY KEY in another table) used to link two tables together.
  • SQL – FROM Keyword
    The FROM keyword is used to specify which table to select or delete data from.
  • SQL – FULL OUTER JOIN Keywords
    The FULL OUTER JOIN keyword returns all rows when there is a match in either the left table or right table.
  • SQL – GROUP BY Keywords
    The GROUP BY keywords are used to group the result set (used with aggregate functions: COUNT, MAX, MIN, SUM, AVG).
  • SQL – HAVING Keyword
    The HAVING keyword is used instead of WHERE with aggregate functions.
  • SQL – IN Keyword
    The IN keyword allows you to specify multiple values in a WHERE clause, and is shorthand for multiple OR conditions.
  • SQL – INDEX Keyword
    Indexes are used to speed up the retrieval of data (searches/queries) from the database.
  • SQL – INNER JOIN Keywords
    The INNER JOIN keywords returns rows that have matching values in both tables.
  • SQL – INSERT INTO Keywords
    The INSERT INTO statement is used to insert new records in a table.
  • SQL – INSERT INTO SELECT Keywords
    The INSERT INTO SELECT keywords copies data from one table and inserts it into another table.
  • SQL – IS NOT NULL Keywords
    The IS NOT NULL keywords are used to test for non-empty values (NOT NULL values).
  • SQL – IS NULL Keywords
    The IS NULL keywords are used to test for empty values (NULL values).
  • SQL – JOIN Keyword
    The JOIN keyword is used in an INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL OUTER JOIN to return matching rows from two tables.
  • SQL – LEFT JOIN Keywords
    The LEFT JOIN keywords return all rows from the left table, and the matching rows from the right table (NULL from the right side if there is no match).
  • SQL – LIKE Keyword
    The LIKE keyword is used in a WHERE clause to search for a specified pattern in a column. It can use two wildcards: % and _.
  • SQL – LIMIT Keyword
    The LIMIT keyword is used to specify the number of records to return (MySQL).
  • SQL – NOT Keyword
    The NOT keyword is used with other SQL keywords to only include rows where a condition is NOT true.
  • SQL – NOT NULL Keywords
    The NOT NULL keywords enforces a column to NOT accept NULL values (a record cannot be inserted/updated without adding a value to that field).
  • SQL – OR Keyword
    The OR keyword is used with the WHERE keyword to include rows where at least one of multiple conditions are true.
  • SQL – ORDER BY Keywords
    The ORDER BY keywords are used to sort the result set using a specified column in ascending order (A – Z) or descending (Z – A) order.
  • SQL – PRIMARY KEY Keywords
    The PRIMARY KEY keywords uniquely identifies each record in a table, which can have only one primary key consisting of a single field or multiple fields.
  • SQL – PROCEDURE Keyword
    The PROCEDURE keyword is used with the CREATE keyword to create a stored procedure (prepared SQL code to be reused many times).
  • SQL – RIGHT JOIN Keywords
    The RIGHT JOIN keywords returns all rows from the right table, and the matching rows from the left table (NULL from the left side if there is no match).
  • SQL – SELECT Keyword
    The SELECT keyword is used to select specified data from a database.
  • SQL – SELECT INTO Keywords
    The SELECT INTO keywords copies data from one table and inserts it into another table.
  • SQL – SET Keyword
    The SET keyword is used with UPDATE to specify which columns and values should be updated in a table.
  • SQL – TABLE Keyword
    The TABLE keyword is used along with CREATE, ALTER, and DROP to manage a database table.
  • SQL – TOP Keyword
    The TOP keyword is used to specify the number of records to return (SQL Server).
  • SQL – TRUNCATE TABLE Keywords
    The TRUNCATE TABLE keywords deletes all the data inside a table, but not the table itself.
  • SQL – UNION Keyword
    The UNION keyword combines the result set of two or more SELECT statements (returning only distinct values).
  • SQL – UNION ALL Keywords
    The UNION ALL keywords combines the result set of two or more SELECT statements (will return duplicate values).
  • SQL – UNIQUE Keyword
    The UNIQUE keyword ensures that all values in a column are unique.
  • SQL – UPDATE Keyword
    The UPDATE keyword is used to update existing rows in a table.
  • SQL – USE Keyword
    The USE keyword specifies the database you intend to work with. The statement is often made when starting work on or switching to a particular database.
  • SQL – VALUES Keyword
    The VALUES keyword specifies the values in an INSERT INTO statement.
  • SQL – VIEW Keyword
    The VIEW keyword is used to CREATE a virtual table based on the result set of an SQL statement.
  • SQL – WHERE Keyword
    The WHERE keyword filters a result set to include only records that fulfill a specified condition or set of conditions.

SQL Notes:

  • Any work being done to modify the structure of a database or delete tables or the the database itself should only be done after making a recent backup

We’d like to acknowledge that we learned a great deal of our coding from W3Schools and TutorialsPoint, borrowing heavily from their teaching process and excellent code examples. We highly recommend both sites to deepen your experience, and further your coding journey. We’re just hitting the basics here at 1SMARTchicken.