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INNER JOIN vs LEFT JOIN performance in SQL Server
I've created SQL command that uses INNER JOIN on 9 tables, anyway this command takes a very long time (more than five minutes). So my folk suggested me to change INNER JOIN to LEFT JOIN because the performance of LEFT JOIN is better, despite what I know. After I changed it, the speed of query got si...
SQL keys, MUL vs PRI vs UNI
What is the difference between MUL , PRI and UNI in MySQL?
4 Answers
4
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PadLeft function in T-SQL
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SQL Server now supports the FORMAT function starting from version 2012, so:
SELECT FORMAT(id, '0000') FROM TableA
will do the trick.
If your id or column is in a varchar and represents a number you convert first:
SELECT...
Difference between database and schema
What's the difference between a Database and a Schema in SQL Server? Both are the containers of tables and data.
5 Answers
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How to check for Is not Null And Is not Empty string in SQL server?
How can we check in a SQL Server WHERE condition whether the column is not null and not the empty string ( '' )?
7 Answe...
How to find Unused Amazon EC2 Security groups
...rom complete. So I decided to write my own script. I used the AWS CLI, MySQL and some “Bash-foo” to perform the following:
Get a list of all EC2 security groups.
I store the group-id, group-name and description in a tabled called “groups” in a MySQL database called aws_security_groups on...
App Inventor 2 LLMAI2Ext 自研拓展：接入DeepSeek、Kimi、通义千问...等国...
...不太便捷，且各种限制。
如今我们又身处AI浪潮之中，包括很多学校在内的国内用户都有AI结合传统的App来开发具有智能App的需求，因此，必须开发拓展以接入国内大模型，对，它专门接国内大模型的，国外的不接。
拓展接口...
SQL Server: What is the difference between CROSS JOIN and FULL OUTER JOIN?
What is the difference between CROSS JOIN and FULL OUTER JOIN in SQL Server?
10 Answers
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MySQL dump by query
Is it possible to do mysqldump by single SQL query ?
9 Answers
9
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'0000-00-00 00:00:00' can not be represented as java.sql.Timestamp error
...n use this JDBC URL directly in your data source configuration:
jdbc:mysql://yourserver:3306/yourdatabase?zeroDateTimeBehavior=convertToNull
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