1. 简单数据记录查询(可用*表示查询全部字段)

SELECT field1, field2, ... 
　　FROM table_name;

1.1 查询结果去重(DISTINCT)

SELECT DISTINCT field1, field2, ...
    FROM table_name;

2. 条件数据记录查询(WHERE)

SELECT *
    FROM table_name
        WHERE 条件;

2.1 范围查询

SELECT *
    FROM table_name
        WHERE field [NOT ]BETWEEN value1 AND value2;

2.2 [非]空值查询

SELECT *
    FROM table_name
        WHERE field IS [NOT ]NULL;

2.3 集合查询

NOT IN 查询的集合中存在NULL则不会有任何查询结果

IN 查询的集合中存在NULL和无NULL的查询结果一致

SELECT *
    FROM table_name
        WHERE field [NOT ]IN (value1, value2, ...);

2.4 模糊查询

“_” 通配符, 匹配单个字符

“%” 通配符, 匹配任意长度的字符

SELECT *
    FROM table_name
        WHERE field [NOT ]LIKE value;

SELECT *
    FROM table_name
        WHERE field REGEXP 正则表达式;

3. 排序数据记录查询

ORDER BY默认为ASC升序排序

SELECT *
    FROM table_name
        ORDER BY field1 [ASC|DESC][, field2 [ASC|DESC], ...]

 4. 限制数据记录查询数量

起始偏移量(跳过的行数)默认为0

SELECT *
    FROM table_name
        LIMIT [起始偏移量, ]显示的行数

5. 统计函数及分组查询

5.1 统计函数

SELECT function(field)
    FROM table_name

COUNT(*) 统计数据记录条数, 不管是否是NULL

COUNT(field) 此统计会忽略该字段的NULL值

5.2 分组查询

可以SELECT*但分组字段每个值只会显示一条记录

SELECT function(field)
    FROM table_name
    　　GROUP BY field1[, field2, ...]

5.3 分组查询–HAVING子句限定分组查询

SELECT function(field)
    FROM table_name
        WHERE CONDITION
        GROUP BY field1[, field2, ...]
            HAVING CONTITION