DO $$BEGINIFEXISTS(SELECTcolumn_nameFROMinformation_schema.columnsWHEREtable_name=tableNameANDcolumn_name=columnName)THENALTERTABLEtableNameDROPCOLUMNcolumnName;ENDIF;END$$; Share Copy link Improve this answer Follow editedAug 15, 2018 at 21:13 ...
This article describes how to delete table columns in SQL Server using SQL Server Management Studio (SSMS) or Transact-SQL.Babala When you delete a column from a table, the column and all the data it contains are deleted.LimitationsYou can't delete a column that has a CHECK constraint. ...
ALTERTABLEdbo.doc_exbDROPCOLUMNcolumn_b; GO 如果该列包含约束或其他依赖项,则会返回一条错误消息。 通过删除引用的约束解决该错误。 有关更多示例,请参阅ALTER TABLE。 相关内容 反馈 此页面是否有帮助? 是否 提供产品反馈| 在Microsoft Q&A 获取帮助
haha,but sometimes i don't wanna list the columns for one unwanted column that really time consuming.Good example:) /* Get the data into a temp table */ SELECT*INTO#TempTable FROMYourTable /* Drop the cloumns that are not needed */ ALTERTABLE#TempTable DROPCOLUMNColumnToDrop /* Get r...
Steps: - name: step_filter_customer1 comment: 过滤掉非法客户 sql: |- SELECT * FROM customers WHERE customers.is_delete=False - name: step_update_distinct type: SELECT_ALL_REPLACE from: step_filter_customer1 columns: - column: discount expr: 0.8 * discount - name: step_drop_distinct type...
查看表结构,相当于desc tblname,show columns from tbname \d tblname \di 查看索引 创建数据库: create database [数据库名]; 删除数据库: drop database [数据库名]; *重命名一个表: alter table [表名A] rename to [表名B]; *删除一个表: ...
1、select col_names from Table_Name 2、alter table tableName drop column columnName 重命名列Python版: df.rename(index={'row1':'A'},columns ={'col1':'B'}) 重命名列SQL版: select col_names as col_name_B from Table_Name 因为一般情况下是没有删除的权限(可以构建临时表),反向思考,删除的...
drop database|schema [ if exists]数据库名 5.查看数据库 在MySQL中,可使用 show databases 或 show schema语句查看可用数据库 show database|schema 二,表 1,创建表 用create table 语句创建表 语句基本格式 create table 表名 ( 字段名1 数据类型 [列级完整性约束条件] [默认值], ...
#TempTableFROM YourTable/* Drop the columns that are not needed */ALTER TABLE #TempTableDROP ...
WHERE parent_object_id = object_id('TableName') AND type = 'D' AND parent_column_id = ( select column_id from sys.columns where object_id = object_id('TableName') and name = 'Accounts' ) set @sql = N'alter table[TableName]drop constraint ' + @default ...