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SQL語法

SQL其次是獨特的一套所謂的語法規則和準則。本教學為您提供了一個快速入門使用SQL列出所有的基本SQL語法:

所有SQL語句開始以類似關鍵字 SELECT, INSERT, UPDATE, DELETE, ALTER, DROP, CREATE, USE, SHOW 並且所有的語句用分號(;)結束。

重要的一點要注意的是,MySQL是不區分大小寫的,這意味著SELECT和select在SQL語句中具有相同的含義,但MySQL在表名有差異。如果使用MySQL的話,那麼需要存在於數據庫中給定的表名。

所有在本教學中所舉的例子已經過在MySQL服務器測試並使用

SQL SELECT 語句:

SELECT column1, column2....columnN
FROM   table_name;

SQL DISTINCT 子句:

SELECT DISTINCT column1, column2....columnN
FROM   table_name;

SQL WHERE 子句:

SELECT column1, column2....columnN
FROM   table_name
WHERE  CONDITION;

SQL AND/OR 子句:

SELECT column1, column2....columnN
FROM   table_name
WHERE  CONDITION-1 {AND|OR} CONDITION-2;

SQL IN 子句:

SELECT column1, column2....columnN
FROM   table_name
WHERE  column_name IN (val-1, val-2,...val-N);

SQL BETWEEN 子句:

SELECT column1, column2....columnN
FROM   table_name
WHERE  column_name BETWEEN val-1 AND val-2;

SQL LIKE 子句:

SELECT column1, column2....columnN
FROM   table_name
WHERE  column_name LIKE { PATTERN };

SQL ORDER BY 子句:

SELECT column1, column2....columnN
FROM   table_name
WHERE  CONDITION
ORDER BY column_name {ASC|DESC};

SQL GROUP BY 子句:

SELECT SUM(column_name)
FROM   table_name
WHERE  CONDITION
GROUP BY column_name;

SQL COUNT 子句:

SELECT COUNT(column_name)
FROM   table_name
WHERE  CONDITION;

SQL HAVING 子句:

SELECT SUM(column_name)
FROM   table_name
WHERE  CONDITION
GROUP BY column_name
HAVING (arithematic function condition);

SQL CREATE TABLE 語句:

CREATE TABLE table_name(
column1 datatype,
column2 datatype,
column3 datatype,
.....
columnN datatype,
PRIMARY KEY( one or more columns )
);

SQL DROP TABLE 語句:

DROP TABLE table_name;

SQL CREATE INDEX 語句 :

CREATE UNIQUE INDEX index_name
ON table_name ( column1, column2,...columnN);

SQL DROP INDEX 語句 :

ALTER TABLE table_name
DROP INDEX index_name;

SQL DESC 語句 :

DESC table_name;

SQL TRUNCATE TABLE 語句:

TRUNCATE TABLE table_name;

SQL ALTER TABLE 語句:

ALTER TABLE table_name {ADD|DROP|MODIFY} column_name {data_ype};

SQL ALTER TABLE 語句 (重命名) :

ALTER TABLE table_name RENAME TO new_table_name;

SQL INSERT INTO 語句:

INSERT INTO table_name( column1, column2....columnN)
VALUES ( value1, value2....valueN);

SQL UPDATE 語句:

UPDATE table_name
SET column1 = value1, column2 = value2....columnN=valueN
[ WHERE  CONDITION ];

SQL DELETE 語句:

DELETE FROM table_name
WHERE  {CONDITION};

SQL CREATE DATABASE 語句:

CREATE DATABASE database_name;

SQL DROP DATABASE 語句:

DROP DATABASE database_name;

SQL USE 語句:

USE database_name;

SQL COMMIT 語句:

COMMIT;

SQL ROLLBACK 語句:

ROLLBACK;