php,$sql = "SELECT a.*, b.* FROM table1 a JOIN table2 b ON a.id = b.a_id";,$result = $conn>query($sql);,
`,,这段代码将连接两个表
table1 和
table2`,并选择它们的所有列。php,$sql = "SELECT a.*, b.* FROM table1 a JOIN table2 b ON a.id = b.a_id";,$result = $conn>query($sql);,
`,,这段代码将连接两个表
table1 和
table2`,并选择它们的所有列。LIMIT
子句来限制返回的记录数。,,``php,$page = isset($_GET['page']) ? (int)$_GET['page'] : 1;,$limit = 10; // 每页显示的记录数,$offset = ($page 1) * $limit;,,$query = "SELECT * FROM your_table LIMIT $offset, $limit";,// 执行查询并处理结果,
``sql,UPDATE table_name SET column_name = REPLACE(column_name, 'old_value', 'new_value') WHERE condition;,
`,,这条SQL语句会将
table_name表中满足
condition条件的记录的
column_name字段中的
old_value替换为
new_value`。sql,SELECT field1, field2 FROM table_name;,
``DISTINCT
关键字来查询不重复的数据。,,``sql,SELECT DISTINCT column_name FROM table_name;,
`,,这将返回
column_name` 列中所有不重复的值。sql,SELECT column_name, COUNT(*),FROM table_name,GROUP BY column_name,HAVING COUNT(*) > 1;,
``php,$sql = "SELECT * FROM users WHERE name LIKE '%John%'";,
``,,这条SQL语句会查找名字中包含"John"的所有用户。Powered By Z-BlogPHP 1.7.3
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