postgresql exists

相關問題 & 資訊整理

postgresql exists

EXISTS. EXISTS (subquery). The argument of EXISTS is an arbitrary SELECT statement, or subquery. The subquery is evaluated to determine whether it returns ... ,The argument of EXISTS is an arbitrary SELECT statement, or subquery. The subquery is evaluated to determine whether it returns any rows. If it returns at least ... , The EXISTS operator tests whether a row(s) exists in a subquery. This means that the operator is used together with a subquery. The Exists ..., ,本節描述PostgreSQL 裡面能用的 SQL 兼容的子查詢資料表達式。所有本節中成文的資料表達式都返回布爾值(真/假)結果。 9.16.1. EXISTS. EXISTS ( ... ,The argument of EXISTS is an arbitrary SELECT statement, or subquery. The subquery is evaluated to determine whether it returns any rows. If it returns at least ... ,The argument of EXISTS is an arbitrary SELECT statement, or subquery. The subquery is evaluated to determine whether it returns any rows. If it returns at least ... ,The argument of EXISTS is an arbitrary SELECT statement, or subquery. The subquery is evaluated to determine whether it returns any rows. If it returns at least ... ,The PostgreSQL EXISTS condition is used in combination with a subquery and is considered "to be met" if the subquery returns at least one row. It can be used ... , Use the EXISTS key word for TRUE / FALSE return: select exists(select 1 from contact where id=12).

相關軟體 PostgreSQL (64-bit) 資訊

PostgreSQL (64-bit)
PostgreSQL 64 位是一個功能強大的開源對象關係數據庫系統。它擁有超過 15 年的積極開發和經過驗證的架構,在可靠性,數據完整性和正確性方面贏得了良好聲譽。它運行在所有主要的操作系統上,包括 Linux,UNIX(AIX,BSD,HP-UX,SGI IRIX,Mac OS X,Solaris,Tru64)和 Windows。  PostgreSQL 64 位是一個功能強大的對象... PostgreSQL (64-bit) 軟體介紹

postgresql exists 相關參考資料
Documentation: 9.5: Subquery Expressions - PostgreSQL

EXISTS. EXISTS (subquery). The argument of EXISTS is an arbitrary SELECT statement, or subquery. The subquery is evaluated to determine whether it returns ...

https://www.postgresql.org

Documentation: 8.0: Subquery Expressions - PostgreSQL

The argument of EXISTS is an arbitrary SELECT statement, or subquery. The subquery is evaluated to determine whether it returns any rows. If it returns at least ...

https://www.postgresql.org

PostgreSQL EXISTS with Examples - Guru99

The EXISTS operator tests whether a row(s) exists in a subquery. This means that the operator is used together with a subquery. The Exists ...

https://www.guru99.com

PostgreSQL EXISTS By Practical Examples

https://www.postgresqltutorial

子查詢資料表達式

本節描述PostgreSQL 裡面能用的 SQL 兼容的子查詢資料表達式。所有本節中成文的資料表達式都返回布爾值(真/假)結果。 9.16.1. EXISTS. EXISTS ( ...

http://twpug.net

Documentation: 8.1: Subquery Expressions - PostgreSQL

The argument of EXISTS is an arbitrary SELECT statement, or subquery. The subquery is evaluated to determine whether it returns any rows. If it returns at least ...

https://www.postgresql.org

Documentation: 7.4: Subquery Expressions - PostgreSQL

The argument of EXISTS is an arbitrary SELECT statement, or subquery. The subquery is evaluated to determine whether it returns any rows. If it returns at least ...

https://www.postgresql.org

Documentation: 9.1: Subquery Expressions - PostgreSQL

The argument of EXISTS is an arbitrary SELECT statement, or subquery. The subquery is evaluated to determine whether it returns any rows. If it returns at least ...

https://www.postgresql.org

PostgreSQL: EXISTS Condition - TechOnTheNet

The PostgreSQL EXISTS condition is used in combination with a subquery and is considered "to be met" if the subquery returns at least one row. It can be used ...

https://www.techonthenet.com

Fastest check if row exists in PostgreSQL - Stack Overflow

Use the EXISTS key word for TRUE / FALSE return: select exists(select 1 from contact where id=12).

https://stackoverflow.com