GROUP BY
子句和 HAVING
子句。,,``sql,SELECT column_name, COUNT(*),FROM table_name,GROUP BY column_name,HAVING COUNT(*) > 1;,
``,,这段代码会返回在指定列中出现次数超过一次的所有值及其出现次数。GROUP BY
子句和 HAVING
子句。,,``sql,SELECT column_name, COUNT(*),FROM table_name,GROUP BY column_name,HAVING COUNT(*) > 1;,
``,,这段代码会返回在指定列中出现次数超过一次的所有值及其出现次数。asp,,
``SELECT * FROM table_name;
,2. 选择特定列:SELECT column1, column2 FROM table_name;
,3. 条件查询:SELECT * FROM table_name WHERE condition;
,4. 排序结果:SELECT * FROM table_name ORDER BY column ASC/DESC;
,5. 聚合函数:SELECT COUNT(*), AVG(column) FROM table_name;
,6. 分组查询:SELECT column, COUNT(*) FROM table_name GROUP BY column;
,7. 连接查询:SELECT a.column1, b.column2 FROM table1 a JOIN table2 b ON a.id = b.id;
,8. 子查询:SELECT * FROM table_name WHERE column IN (SELECT column FROM another_table);
sql,SELECT column_name FROM table_name WHERE condition;,
`,,
column_name是你要查询的text类型列的名称,
table_name是表的名称,
condition`是查询条件。sql,SELECT * FROM post_offices WHERE city = '北京';,
`,,这条SQL语句将从名为
post_offices的表中选择所有列(使用星号
*表示),city
列的值等于'北京'。这将返回满足条件的所有邮局记录。请确保将表名和列名替换为您实际数据库中的相应名称。"sql,SELECT column_name, COUNT(*),FROM table_name,GROUP BY column_name,HAVING COUNT(*) > 1;,
`,,这条语句会返回
table_name 表中
column_name` 列值相同的所有记录的数量,并且只显示那些出现次数超过一次的记录。table_name
的所有记录的标准 SQL 语句。Powered By Z-BlogPHP 1.7.3
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