SQL之后是一组称为语法的独特规则和指南.本教程通过列出所有基本的SQL语法为您提供SQL快速入门.
所有SQL语句都以SELECT,INSERT,UPDATE,DELETE,ALTER,DROP等任何关键字开头. ,CREATE,USE,SHOW和所有语句以分号(;)结尾.
这里要注意的最重要的一点是SQL不区分大小写,这意味着SELECT和select有SQL语句中的含义相同.然而,MySQL在表名中有所不同.因此,如果您正在使用MySQL,那么您需要提供数据库中存在的表名.
All本教程中给出的示例已经过MySQL服务器测试.
SELECT column1,column2 .... columnN FROM table_name;
SELECT DISTINCT column1,column2 ... .columnN FROM table_name;
SELECT column1,column2 .... columnN FROM table_name WHERE CONDITION;
SELECT column1,column2 .. ..columnN FROM table_name WHERE CONDITION-1 {AND | OR} CONDITION-2;
SELECT column1,column2 .... columnN FROM table_name WHERE column_name IN(val-1,val-2,... val-N);
SELECT column1,column2 .... columnN FROM table_name WHERE column_name BETWEEN val-1 AND val-2;
SELECT column1,column2 .... columnN FROM table_name WHERE column_name LIKE {PATTERN};
SELECT column1,column2 ... .columnN FROM table_name WHERE CONDITION ORDER BY column_name {ASC | DESC};
SELECT SUM(column_name) FROM table_name WHERE CONDITION GROUP BY column_name;
SELECT COUNT(column_name) FROM table_name WHERE CONDITION;
SELECT SUM(column_name) FROM table_name WHERE CONDITION GROUP BY column_name HAVING(arithematic function condition);
CREATE TABLE table_name( column1数据类型, column2数据类型, column3数据类型, ..... columnN数据类型, PRIMARY KEY(一列或多列) );
DROP TABLE table_name;
CREATE UNIQUE INDEX index_name ON table_name(column1,column2,... columnN);
ALTER TABLE table_name DROP INDEX index_name;
DESC table_name;
TRUNCATE TABLE table_name;
ALTER TABLE table_name {ADD | DROP | MODIFY} column_name {data_ype};
ALTER TABLE table_name RENAME TO new_table_name;
INSERT INTO table_name(column1,column2 .... columnN) VALUES(value1,value2 .... valueN);
UPDATE table_name SET column1 = value1,column2 = value2 .... columnN = valueN [WHERE CONDITION];
DELETE FROM table_name WHERE {条件};
CREATE DATABASE database_name;
DROP DATABASE database_name;
USE database_name;
COMMIT;
ROLLBACK;