[ HAVING condition [, ...] ] [ WINDOW window_name AS ( window_definition ) [, ...] ] [ { UNION | INTERSECT | EXCEPT } [ ALL | DISTINCT ] select ] [ ORDER BY expression [ ASC | DESC | USING operator ] [ NULLS { FIRST | LAST } ] [, ...] ] [ LIMIT { count | ALL ...
select deptno,avg(sal) from emp group by deptno; 注意:group by 后面跟多个列时,只有当多个列的值同时相等时,它才会分为同一个组;--select job,deptno,count(*) from emp group by job,deptno; having:它是对分组后的数据进行筛选,条件表达式中可以使用聚合函数 --求平均工资大于2000的部门编号和平均工资...
其中,column_name是要获取行号的列名,table_name是表名,condition是满足的条件。 使用子查询:可以使用子查询来获取满足条件的行的行号。示例查询语句如下: 代码语言:txt 复制 SELECT column_name, ( SELECT COUNT(*) FROM table_name AS t2 WHERE t2.column_name <= t1.column_name ) AS row_number FRO...
CREATE TABLE COMPANY1( ID INT PRIMARY KEY NOT NULL, NAME TEXT NOT NULL, AGE INT NOT NULL, ADDRESS CHAR(50), SALARY REAL ); WITH moved_rows AS ( DELETE FROM COMPANY WHERE SALARY >= 30000 RETURNING * ) INSERT INTO COMPANY1 (SELECT * FROM moved_rows); 1. 2. 3. 4. 5. 6. 7....
CREATE TABLE on_hand ( item inventory_item, count integer ); INSERT INTO on_hand VALUES (ROW('fuzzy dice', 42, 1.99), 1000); SELECT * FROM on_hand; item | count ---+--- ("fuzzy dice",42,1.99) | 1000 ROW语句用于构建组合类型的值。 创建数据表的同时,会创建同名的type,如 -- ...
[ GROUP BY expression [, ...] ] [ HAVING condition [, ...] ] [ { UNION | INTERSECT | EXCEPT } [ ALL ] select ] [ ORDER BY expression [ ASC | DESC | USING operator ] [, ...] ] [ LIMIT { count | ALL } ] [ OFFSET start ] [ FOR UPDATE [ OF table_name [, ...] ...
{ "invalid_row_count_in_limit_clause", ERRCODE_INVALID_ROW_COUNT_IN_LIMIT_CLAUSE }, { "invalid_row_count_in_result_offset_clause", ERRCODE_INVALID_ROW_COUNT_IN_RESULT_OFFSET_CLAUSE }, { "invalid_tablesample_argument", ERRCODE_INVALID_TABLESAMPLE_ARGUMENT }, { "invalid_tablesample_repeat", ...
substr(string, from [, count]) text 抽取子字串。 substr('alphabet', 3, 2) ph to_ascii(text [, encoding]) text 把text从其它编码转换为ASCII。 to_ascii('Karel') Karel to_hex(number int/bigint) text 把number转换成其对应地十六进制表现形式。 to_hex(9223372036854775807) 7fffffffffffffff ...
Oracle中,CONNECT BY 用于存在上下级等层级关系的数据表进行递归查询。语法格式: START WITH condition1 CONNECT BY [ NOCYCLE ] condition2。在PostgreSQL通过Recursive Common Table Expression来实现此功能,主要是把START WITH... CONNECT BY Prior拆成两个部分,查询表一致,但条件不一致,用UNION ALL合并。
parse->limitCount = preprocess_expression(root, parse->limitCount, EXPRKIND_LIMIT); root->append_rel_list = (List *) preprocess_expression(root, (Node*) root->append_rel_list, EXPRKIND_APPINFO);/*Also need to preprocess expressions for function and values RTEs*/foreach(l, parse->rtable...