1 SELECT * FROM INFORMATION_SCHEMA.COLUMNS where table_name = '表名' 二、Oracle版本: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 CREATE OR REPLACE FUNCTION F_SELECTALL (v_table IN VARCHAR2, v_prefix IN VARCHAR2) RETURN VARCHAR2 IS Rtsql VARCHAR2 (1000); pr...
百度试题 题目在SQL中,要查询表中的所有记录,可以使用哪个语句?(选择题) A. SELECT * FROM table; B. SELECT table; C. SELECT * FROM table WHERE 1=1; D. SELECT table WHERE 1=1; 相关知识点: 试题来源: 解析 A null 反馈 收藏
SELECT column_name, aggregate_function(column_name) FROM table_name WHERE column_name operator value GROUP BY column_name; GROUP BY关键字可以将查询的数据行根据某些列分组。 student表中查询每个院系有多少人,为统计的人数列取别名sum_of_dept: mysql> select dept,count(All name) as sum_of_dept fro...
SELECTcolumn1,column2,...FROMtable_name; 其中,column1,column2,等是您要从表中选择的字段名称,而table_name是您要选择数据的表的名称。 如果要选择表中的所有列,您可以使用SELECT *语法。 以下是一些示例: 从Customers表中选择CustomerName和City列的数据: 代码语言:sql 复制 SELECTCustomerName,CityFROMCustome...
syntaxsql 复制 SELECT [ ALL | DISTINCT ] [ TOP ( expression ) [ PERCENT ] [ WITH TIES ] ] <select_list> <select_list> ::= { * | { table_name | view_name | table_alias }.* | { [ { table_name | view_name | table_alias }. ] { column_name | $IDENTITY | $ROWGUID }...
syntaxsql 複製 SELECT [ ALL | DISTINCT ] [ TOP ( expression ) [ PERCENT ] [ WITH TIES ] ] <select_list> <select_list> ::= { * | { table_name | view_name | table_alias }.* | { [ { table_name | view_name | table_alias }. ] { column_name | $IDENTITY | $ROWGUID }...
select decode(t.num_rows, 0, t.table_name, null) 无数据的表,decode(t.num_rows, 0, null, t.table_name) 有数据的表 from user_tables t where t.table_name in (SELECT t1.table_name FROM All_All_Tables t1);SQL2 select decode(t.num_rows, 0, t.table_name, null) 无...
简化版查询语法,功能相当于select * from table_name。 TABLE { ONLY {(table_name)| table_name} | table_name [ * ]}; 参数说明 WITH [ RECURSIVE ] with_query [, ...] 用于声明一个或多个可以在主查询中通过名字引用的子查询,相当于临时表。 如果声明了RECURSIVE,那么允许SELECT子查询通过名字...
SELECT Concat(RTrim(vend_name) , '(' , RTrim(vend_country) , ')') AS vend_title FROM vendors ORDER BY vend_name; 别名除了用于列名和计算字段外,sql还允许给表名起别名。一可以缩短sql语句,二允许在单条SELECT 语句中多次使用相同的表 SELECTcust_name , cust_contact ...
syntaxsql [WITH<common_table_expression>[ , ...n ] ]SELECT<select_criteria>[ ; ]<select_criteria>::=[TOP(top_expression) ] [ALL|DISTINCT] { * |column_name| expression } [ , ...n ] [FROM{table_source} [ , ...n ] ] [WHERE<search_condition>] [GROUPBY<group_by_clause>] [HA...