To define a foreign key, you can use a foreign key constraint. PostgreSQL foreign key constraint syntax The following illustrates a foreign key constraint syntax: [CONSTRAINT fk_name] FOREIGN KEY(fk_columns) REFERENCES parent_table(parent_key_columns) [ON DELETE delete_action] [ON UPDATE update...
-D, --define=VARNAME=VALUE定义变量以供自定义脚本使用 -j, --jobs=NUM指定线程数 -l, --log将事务时间写入日志文件 -L, --latency-limit=NUM将持续时间超过M毫秒的事务计数为延迟 -M, --protocol=simple|extended|prepared查询的协议(默认:simple) ...
Foreign key –show you how to define foreign key constraints when creating a new table or adding foreign key constraints for existing tables. DELETE CASCADE –show you how to automatically delete rows in child tables when the corresponding rows in the parent table are deleted. CHECK constraint –...
May 3, 2024 by Robert GravelleOne of PostgreSQL's key features is the ability to enforce various constraints on data, ensuring data integrity and reliability. Today's blog article will provide an overview of PostgreSQL's various constraint types and explore their usage with examples from the free...
(this is also a warning class per the SQL standard) */ #define ERRCODE_NO_DATA MAKE_SQLSTATE('0','2','0','0','0') #define ERRCODE_NO_ADDITIONAL_DYNAMIC_RESULT_SETS_RETURNED MAKE_SQLSTATE('0','2','0','0','1') /* Class 03 - SQL Statement Not Yet Complete */ #define ...
Partitioned tables do not support UNIQUE, PRIMARY KEY, EXCLUDE,orFOREIGN KEY constraints; however, you can define these constraints on individual partitions. When using range partitioning, a NOT NULL constraint isaddedto each non-expression column in the partition key. ...
Command:CREATETRIGGERDescription:define anewtriggerSyntax:CREATE[CONSTRAINT]TRIGGERname{BEFORE|AFTER|INSTEADOF}{event[OR...]}ONtable_name[FROMreferenced_table_name]{NOTDEFERRABLE|[DEFERRABLE]{INITIALLYIMMEDIATE|INITIALLYDEFERRED}}[FOR[EACH]{ROW|STATEMENT}][WHEN(condition)]EXECUTEPROCEDUREfunction_name(argume...
#define ShareLock 5 /* CREATE INDEX (WITHOUT CONCURRENTLY) */ #define ShareRowExclusiveLock 6 /* CREATE TRIGGER and many forms of ALTER TABLE, like EXCLUSIVE MODE, but allows ROW SHARE */ #define ExclusiveLock 7 /* REFRESH MATERIALIZED VIEW CONCURRENTLY, blocks ROW SHARE/SELECT...FOR UPDATE...
postgres=#\helpcreatetablespace;Command:CREATETABLESPACEDescription:defineanewtablespaceSyntax:CREATETABLESPACEtablespace_name[OWNER{new_owner|CURRENT_ROLE|CURRENT_USER|SESSION_USER}]LOCATION'directory'[WITH(tablespace_option=value[,...])]--创建表空间abc_tbs,实现准备对应的目录[postgres@centos79~]$ls-lrt...
1 Here is an example using sum: 1 There are options to define the window frame in other ways, but this tutorial does not cover them. See ??? for details. 21 Advanced Features SELECT salary, sum(salary) OVER () FROM empsalary; salary | sum ---+--- 5200 | 47100 5000 | 47100 ...