CREATE TABLE new_table AS (SELECT column_1, column2, ... column_n FROM old_table); For example: CREATE TABLE suppliers AS (SELECT id, address, city, state, zip FROM companies WHERE id > 1000); This would create a new table calledsuppliers, but the new table would only include the ...
column_name是要更改、添加或除去的列的名称。对于新列,如果数据类型为 timestamp,column_name 可以省略。对于 timestamp 数据类型的列,如果未指定 column_name,将使用名称 timestamp。new_data_type是要更改的列的新数据类型。要更改的列的 new_data_type 应符合下列准则: ...
DELIMITER // CREATE PROCEDURE my_procedure (IN param1 INT, OUT result INT) BEGIN -- 存储过程的SQL语句SELECT column1 INTO result FROM my_table WHERE another_column = param1; END // DELIMITER ; 在上述示例中: my_procedure 是存储过程的名称。 (IN param1 INT, OUT result INT) 定义了输入参数...
CREATE TABLE table_name ( column1_name datatype, column2_name datatype, column3_name datatype, column4_name datatype, column5_name datatype,) CREATE TABLE table_name ( column1_name datatype, column2_name datatype, column3_name datatype, column4_name datatype, column5_name datatype,) ...
SELECT column, another_column, … FROM mytable WHERE condition(s) ORDER BY column ASC/DESC; 4.结果筛选 去除重复行:在SQL中,DISTINCT关键字应用于所有的列,而不仅仅是第一列。当你在SELECT语句中使用DISTINCT关键字时,它会考虑所有列的组合来确定唯一性 ...
CREATE DATABASE [IF NOT EXISTS] db_name; 举例: 新建数据库 db_test CREATE DATABASE db_test; Create Table 该语句用于创建表(table) 语法: CREATE [EXTERNAL] TABLE [IF NOT EXISTS] [database.]table_name (column_definition[, column_definition, ...]) [ENGINE = [olap|mysql|broker]] [key_de...
alter table database.owner.table_name add column_name char(2) null ... sp_help table_name --- 显示表已有特征 create table table_name (name char(20), age smallint, lname varchar(30)) insert into table_name select ... --- 实现删除列的方法(创建新表) alter table table...
(col3); Column col4; col4 =newColumn(tb,"Date", DataType.DateTime); col4.Nullable =false; tb.Columns.Add(col4);//Create the table on the instance of SQL Server.tb.Create();//Add another column.Column col5; col5 =newColumn(tb,"ExpiryDate", DataType.DateTime); col5...
Can wildcards be used on datetime column? can you add colour to a fields output in T-SQL? Can you change the value of yes or no instead of true or false use data type (BIT) ? Can you have a TRY CATCH in dynamic SQL? Can you Select From (another query)? Can you use a case ...
-- 把myTable下的id=2的数据的 title列 改成 'new title'update myTable set title = 'new title' where id = 2```### 表内数据的查询`SELECT```sqlSELECT DISTINCT column, AGG_FUNC(column_or_expression), …FROM mytable JOIN another_table ON mytable.column = another_table.column WHERE cons...