Pl sql inserting updating

22-Sep-2017 17:36

There are two types of triggers based on the which level it is triggered.1) Row level trigger - An event is triggered for each row upated, inserted or deleted.2) Statement level trigger - An event is triggered for each sql statement executed.The following hierarchy is followed when a trigger is fired. 2) Next BEFORE row level trigger fires, once for each row affected.

This events will alternates between BEFORE and AFTER row level triggers.

Recall that in My SQL, a primary key is simply a unique index named PRIMARY.

Any data that violates any unique index will cause the same problem. For example, I might export some data to a spreadsheet, send it to a client, and the client might update or add some data and return the spreadsheet to me.

The below statement shows the structure of the view 'USER_TRIGGERS' NAME Type -------------------------------------------------------- TRIGGER_NAME VARCHAR2(30) TRIGGER_TYPE VARCHAR2(16) TRIGGER_EVENT VARCHAR2(75) TABLE_OWNER VARCHAR2(30) BASE_OBJECT_TYPE VARCHAR2(16) TABLE_NAME VARCHAR2(30) COLUMN_NAME VARCHAR2(4000) REFERENCING_NAMES VARCHAR2(128) WHEN_CLAUSE VARCHAR2(4000) STATUS VARCHAR2(8) DESCRIPTION VARCHAR2(4000) ACTION_TYPE VARCHAR2(11) TRIGGER_BODY LONG This view stores information about header and body of the trigger.

This is an undesirable situation where more than one trigger enter into an infinite loop.1) Create the 'product' table and 'product_price_history' table Once the above update query is executed, the trigger fires and updates the 'product_price_history' table.