search
HomeDatabaseSQLHow to delete data using delete statement

How to delete data using delete statement

How to use delete statement to delete data?

Create a temporary table to demonstrate the use of delete in sqlserver syntax

Recommended: "SQL Tutorial"

IF OBJECT_ID('tempdb..#tblDelete') IS NOT NULL DROP TABLE #tblDelete; 
CREATE TABLE #tblDelete(
    Code varchar(50),        
    Total int    
);

How to delete data using delete statement

Insert a few test rows into the temporary table #tblDelete to demonstrate how to delete data

insert into #tblDelete(Code, Total) values('Code1', 30);
insert into #tblDelete(Code, Total) values('Code2', 40);
insert into #tblDelete(Code, Total) values('Code3', 50);
insert into #tblDelete(Code, Total) values('Code4', 6);

How to delete data using delete statement

Query the temporary table#tblDelete Test data in

select * from #tblDelete;

How to delete data using delete statement

Delete the record with Code field = Code3 in temporary table #tblDelete, use the following delete statement

delete #tblDelete where Code = 'Code3'

How to delete data using delete statement

Query the temporary table again#tblDelete results, you can see that the record of Code3 is gone

select * from #tblDelete;

How to delete data using delete statement

Delete the temporary table#tblDelete in the Code field =Code2 To record, use the delete statement below.

Note that there is a from keyword after the delete statement below. This keyword can be omitted, but it is recommended not to omit it

delete from #tblDelete where Code = 'Code2'

How to delete data using delete statement

Query temporarily again As a result of table #tblDelete, you can see that the record of Code2 is gone

select * from #tblDelete;

How to delete data using delete statement

Finally, if you want to quickly delete all the data in the table, there are two ways below. The second way is faster

delete from #tblDelete;
truncate table #tblDelete;

How to delete data using delete statement

The above is the detailed content of How to delete data using delete statement. For more information, please follow other related articles on the PHP Chinese website!

Statement
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
OLTP vs OLAP: What about big data?OLTP vs OLAP: What about big data?May 14, 2025 am 12:06 AM

OLTPandOLAParebothessentialforbigdata:OLTPhandlesreal-timetransactions,whileOLAPanalyzeslargedatasets.1)OLTPrequiresscalingwithtechnologieslikeNoSQLforbigdata,facingchallengesinconsistencyandsharding.2)OLAPusesHadoopandSparktoprocessbigdata,withsetup

What is Pattern Matching in SQL and How Does It Work?What is Pattern Matching in SQL and How Does It Work?May 13, 2025 pm 04:09 PM

PatternmatchinginSQLusestheLIKEoperatorandregularexpressionstosearchfortextpatterns.Itenablesflexibledataqueryingwithwildcardslike%and_,andregexforcomplexmatches.It'sversatilebutrequirescarefulusetoavoidperformanceissuesandoveruse.

Learning SQL: Understanding the Challenges and RewardsLearning SQL: Understanding the Challenges and RewardsMay 11, 2025 am 12:16 AM

Learning SQL requires mastering basic knowledge, core queries, complex JOIN operations and performance optimization. 1. Understand basic concepts such as tables, rows, and columns and different SQL dialects. 2. Proficient in using SELECT statements for querying. 3. Master the JOIN operation to obtain data from multiple tables. 4. Optimize query performance, avoid common errors, and use index and EXPLAIN commands.

SQL: Unveiling Its Purpose and FunctionalitySQL: Unveiling Its Purpose and FunctionalityMay 10, 2025 am 12:20 AM

The core concepts of SQL include CRUD operations, query optimization and performance improvement. 1) SQL is used to manage and operate relational databases and supports CRUD operations. 2) Query optimization involves the parsing, optimization and execution stages. 3) Performance improvement can be achieved through the use of indexes, avoiding SELECT*, selecting the appropriate JOIN type and pagination query.

SQL Security Best Practices: Protecting Your Database from VulnerabilitiesSQL Security Best Practices: Protecting Your Database from VulnerabilitiesMay 09, 2025 am 12:23 AM

Best practices to prevent SQL injection include: 1) using parameterized queries, 2) input validation, 3) minimum permission principle, and 4) using ORM framework. Through these methods, the database can be effectively protected from SQL injection and other security threats.

MySQL: A Practical Application of SQLMySQL: A Practical Application of SQLMay 08, 2025 am 12:12 AM

MySQL is popular because of its excellent performance and ease of use and maintenance. 1. Create database and tables: Use the CREATEDATABASE and CREATETABLE commands. 2. Insert and query data: operate data through INSERTINTO and SELECT statements. 3. Optimize query: Use indexes and EXPLAIN statements to improve performance.

Comparing SQL and MySQL: Syntax and FeaturesComparing SQL and MySQL: Syntax and FeaturesMay 07, 2025 am 12:11 AM

The difference and connection between SQL and MySQL are as follows: 1.SQL is a standard language used to manage relational databases, and MySQL is a database management system based on SQL. 2.SQL provides basic CRUD operations, and MySQL adds stored procedures, triggers and other functions on this basis. 3. SQL syntax standardization, MySQL has been improved in some places, such as LIMIT used to limit the number of returned rows. 4. In the usage example, the query syntax of SQL and MySQL is slightly different, and the JOIN and GROUPBY of MySQL are more intuitive. 5. Common errors include syntax errors and performance issues. MySQL's EXPLAIN command can be used for debugging and optimizing queries.

SQL: A Guide for Beginners - Is It Easy to Learn?SQL: A Guide for Beginners - Is It Easy to Learn?May 06, 2025 am 12:06 AM

SQLiseasytolearnforbeginnersduetoitsstraightforwardsyntaxandbasicoperations,butmasteringitinvolvescomplexconcepts.1)StartwithsimplequerieslikeSELECT,INSERT,UPDATE,DELETE.2)PracticeregularlyusingplatformslikeLeetCodeorSQLFiddle.3)Understanddatabasedes

See all articles

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 Article

Hot Tools

mPDF

mPDF

mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

WebStorm Mac version

WebStorm Mac version

Useful JavaScript development tools

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver Mac version

Dreamweaver Mac version

Visual web development tools