Home Database Mysql Tutorial mssql数据库中的表、字段sql语句

mssql数据库中的表、字段sql语句

Jun 07, 2016 pm 06:01 PM
sql statement Field

在数据库中创建的每个对象(例如约束、默认值、日志、规则以及存储过程)都对应一行。

mssql update from 语法
代码如下:
update a set a.columnname=b.columnname from a,b where b.id=1

1.系统表sysobjects

在数据库中创建的每个对象(例如约束、默认值、日志、规则以及存储过程)都对应一行。

参考

2.syscolumns

为每个表和视图中的每列返回一行,并为数据库中的存储过程的每个参数返回一行。

参考

删除某数据库内的表

declare dlist cursor for
select name from sysobjects where xtype='U'
open dlist
declare @n varchar(4000)
fetch next from dlist into @n
while @@fetch_status=0
begin
declare @es varchar(4000)
set @es='DROP table
exec( @es)
fetch next from dlist into @n
end
close dlist
DEALLOCATE dlist

Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

How to create tables with sql server using sql statement How to create tables with sql server using sql statement Apr 09, 2025 pm 03:48 PM

How to create tables using SQL statements in SQL Server: Open SQL Server Management Studio and connect to the database server. Select the database to create the table. Enter the CREATE TABLE statement to specify the table name, column name, data type, and constraints. Click the Execute button to create the table.

How to judge SQL injection How to judge SQL injection Apr 09, 2025 pm 04:18 PM

Methods to judge SQL injection include: detecting suspicious input, viewing original SQL statements, using detection tools, viewing database logs, and performing penetration testing. After the injection is detected, take measures to patch vulnerabilities, verify patches, monitor regularly, and improve developer awareness.

How to write a tutorial on how to connect three tables in SQL statements How to write a tutorial on how to connect three tables in SQL statements Apr 09, 2025 pm 02:03 PM

This article introduces a detailed tutorial on joining three tables using SQL statements to guide readers step by step how to effectively correlate data in different tables. With examples and detailed syntax explanations, this article will help you master the joining techniques of tables in SQL, so that you can efficiently retrieve associated information from the database.

How to check SQL statements How to check SQL statements Apr 09, 2025 pm 04:36 PM

The methods to check SQL statements are: Syntax checking: Use the SQL editor or IDE. Logical check: Verify table name, column name, condition, and data type. Performance Check: Use EXPLAIN or ANALYZE to check indexes and optimize queries. Other checks: Check variables, permissions, and test queries.

How to use SQL statement insert How to use SQL statement insert Apr 09, 2025 pm 06:15 PM

The SQL INSERT statement is used to insert data into a table. The steps include: specify the target table to list the columns to be inserted. Specify the value to be inserted (the order of values ​​must correspond to the column name)

How to create an oracle database How to create an oracle database How to create an oracle database How to create an oracle database Apr 11, 2025 pm 02:33 PM

Creating an Oracle database is not easy, you need to understand the underlying mechanism. 1. You need to understand the concepts of database and Oracle DBMS; 2. Master the core concepts such as SID, CDB (container database), PDB (pluggable database); 3. Use SQL*Plus to create CDB, and then create PDB, you need to specify parameters such as size, number of data files, and paths; 4. Advanced applications need to adjust the character set, memory and other parameters, and perform performance tuning; 5. Pay attention to disk space, permissions and parameter settings, and continuously monitor and optimize database performance. Only by mastering it skillfully requires continuous practice can you truly understand the creation and management of Oracle databases.

Do mysql need to pay Do mysql need to pay Apr 08, 2025 pm 05:36 PM

MySQL has a free community version and a paid enterprise version. The community version can be used and modified for free, but the support is limited and is suitable for applications with low stability requirements and strong technical capabilities. The Enterprise Edition provides comprehensive commercial support for applications that require a stable, reliable, high-performance database and willing to pay for support. Factors considered when choosing a version include application criticality, budgeting, and technical skills. There is no perfect option, only the most suitable option, and you need to choose carefully according to the specific situation.

How to recover data after SQL deletes rows How to recover data after SQL deletes rows Apr 09, 2025 pm 12:21 PM

Recovering deleted rows directly from the database is usually impossible unless there is a backup or transaction rollback mechanism. Key point: Transaction rollback: Execute ROLLBACK before the transaction is committed to recover data. Backup: Regular backup of the database can be used to quickly restore data. Database snapshot: You can create a read-only copy of the database and restore the data after the data is deleted accidentally. Use DELETE statement with caution: Check the conditions carefully to avoid accidentally deleting data. Use the WHERE clause: explicitly specify the data to be deleted. Use the test environment: Test before performing a DELETE operation.

See all articles