SQL快速参考

SQL快速参考，数据库常用语句与语法，日常使用

SQL快速参考

• AND / OR
  • SELECT column_name(s) FROM table_name WHERE condition AND|OR condition
• ALTER TABLE (add column)
  • ALTER TABLE table_name ADD column_name datatype
• ALTER TABLE (drop column)
  • ALTER TABLE table_name DROP COLUMN column_name
• AS (alias for column)
  • SELECT column_name AS column_alias FROM table_name
• BETWEEN
  • SELECT column_name(s) FROM table_name WHERE column_name BETWEEN value1 AND value2
• CREATE DATABASE
  • CREATE DATABASE database_name
• CREATE INDEX
  • CREATE INDEX index_name ON table_name (column_name)
• CREATE TABLE
  • CREATE TABLE table_name ( column_name1 data_type, column_name2 data_type, ....... )
• CREATE UNIQUE INDEX
  • CREATE UNIQUE INDEX index_name ON table_name (column_name)
• CREATE VIEW
  • CREATE VIEW view_name AS SELECT column_name(s) FROM table_name WHERE condition
• DELETE FROM
  • DELETE FROM table_name (Note: Deletes the entire table!!) or DELETE FROM table_name WHERE condition
• DROP DATABASE
  • DROP DATABASE database_name
• DROP INDEX
  • DROP INDEX table_name.index_name
• DROP TABLE
  • DROP TABLE table_name
• GROUP BY
  • SELECT column_name1,SUM(column_name2) FROM table_name GROUP BY column_name1
• HAVING
  • SELECT column_name1,SUM(column_name2) FROM table_name GROUP BY column_name1 HAVING SUM(column_name2) condition value
• IN
  • SELECT column_name(s) FROM table_name WHERE column_name IN (value1,value2,..)
• INSERT INTO
  • INSERT INTO table_name VALUES (value1, value2,....) or INSERT INTO table_name (column_name1, column_name2,...) VALUES (value1, value2,....)
• LIKE
  • SELECT column_name(s) FROM table_name WHERE column_name LIKE pattern
• ORDER BY
  • SELECT column_name(s) FROM table_name ORDER BY column_name [ASC|DESC]
• SELECT
  • SELECT column_name(s) FROM table_name
• SELECT *
  • SELECT * FROM table_name
• SELECT DISTINCT
  • SELECT DISTINCT column_name(s) FROM table_name
• SELECT INTO (used to create backup copies of tables)
  • SELECT * INTO new_table_name FROM original_table_name or SELECT column_name(s) INTO new_table_name FROM original_table_name
• TRUNCATE TABLE (deletes only the data inside the table)
  • TRUNCATE TABLE table_name
• UPDATE
  • UPDATE table_name SET column_name=new_value [, column_name=new_value] WHERE column_name=some_value
• WHERE
  • SELECT column_name(s) FROM table_name WHERE condition