在PostgreSQL中,触发器(Trigger)是一种特殊的存储过程,它会在对表执行特定操作(如INSERT、UPDATE或DELETE)时自动执行。触发器可以用于实现复杂的业务逻辑,如数据验证、日志记录、数据转换等。 相关优势 自动化:触发器可以在数据库层面自动执行某些操作,无需编写额外的应用程序代码。
Create Trigger Start the application and connect to the Postgres database. Navigate to Triggers section and click on Add Trigger. Fill in required parameters and save the trigger.Conclusion Triggers in PostgreSQL provide a powerful mechanism for automating actions and enforcing data integrity. By ...
runoobdb=#INSERTINTOCOMPANY (ID,NAME,AGE,ADDRESS,SALARY,JOIN_DATE)VALUES(3,'Teddy',23,'Norway',20000.00,DEFAULT);INSERT01 插入多行 runoobdb=#INSERTINTOCOMPANY (ID,NAME,AGE,ADDRESS,SALARY,JOIN_DATE)VALUES(4,'Mark',25,'Rich-Mond ',65000.00,'2007-12-13'), (5,'David',27,'Texas',85000....
PostgreSQL trigger functions are similar to regularuser-defined functions. They are invoked when a particular database event (for example INSERT, UPDATE, DELETE) occurs. Triggers do not take any argument or parameters and return a value having a typetrigger. What are Triggers in Postgres? Trigge...
The trigger will cause the rowa, a+1, bto be inserted into columnsx, y, z Edit Here's an approach that might work: DROPTABLEIFEXISTStbl;CREATETABLEtbl ( xinteger, yinteger, zinteger);INSERTINTOtbl(x, z)SELECTx, x+cast(3*random()ASinteger)FROMgenerate_series(1,2)ASt(x);CREATEOR...
CREATE [ OR REPLACE ] TRIGGER <name> { BEFORE | AFTER | INSTEAD OF } { INSERT | UPDATE | DELETE | TRUNCATE } [ OR { INSERT | UPDATE | DELETE | TRUNCATE} ] [, ...] ON [ REFERENCING { OLD AS <old> | NEW AS <new> } ...] [ FOR ...
CREATE OR REPLACE TRIGGER user_audit_trig AFTER INSERT OR UPDATE OR DELETE ON emp DECLARE v_action VARCHAR2(24); BEGIN IF INSERTING THEN v_action := ' added employee(s) on '; ELSIF UPDATING THEN v_action := ' updated employee(s) on '; ELSIF DELETING THEN v_action ...
postgres=# 1. 2. 3. 4. 创建表 创建表之前要连接指定的数据库 \c test; CREATE TABLE table_name( column1 datatype, column2 datatype, column3 datatype, ... columnN datatype, PRIMARY KEY( one or more columns ) ); 1. 2. 3.
-- 创建触发器 CREATE TRIGGER my_trigger BEFORE INSERT ON your_table FOR EACH ROW BEGIN -- 设置插入数据的时间值 :NEW.column_name := sysdate + interval '30' minute; END; / 在上述示例中,my_trigger是触发器的名称,your_table是要插入数据的表名,column_name是要设置时间值的列名。通过将...
public | postgres schema01 | postgres (2 rows) 1. 2. 3. 4. 5. 6. 7. 8. 9. 在schema中创建对象 db01=# create table schema01.t1(id int); CREATE TABLE db01=# insert into schema01.t1 values(1); INSERT 0 1 db01=# select * from t1; ...