Summary of key points to note about view updates

View can be updated and the definition of query in the view is related to the one. Those in MySQL try to make them unreasonable? The following types of views are not updated 1. SQL statements including the following keywords: polymerization functions (SUM, MIN, MAX, Count) by, having, union, or uinon all2. Constant view 3.Select Contains a subquery 4.join 5.from a non-updatable attempt 6.The subquery of the where clause refers to the table in the from clause 2. Update view condition restrictions WITH [CASCADED | LOCAL] CHECK OPTION determines the conditions for updating the view. LOCAL means CASCADED can be updated as long as the conditions of this view are met. All view conditions for this view must be met before it can be updated. If it is not clear whether it is local or cascade, the default is cascade. For ease of understanding, the data structure of the known t3 table is explained through examples as follows: -- Create a view ldq_

1. Detailed explanation of view update in mysql

Introduction: view Updateability is related to the definition of the query in the view. 1. What are those in MySQL that try to make it non-updatable? The following types of views are not updatable 1. SQL statements containing the following keywords: aggregate functions (sum, min, max, count), distinct, group by, having, union or uinon all 2. Constant views 3. Select contains sub Query 4.join5.from a non-updatable attempt 6.wh

2. mysql view modification and view update syntax example

Introduction: We talked about the creation of views earlier. In today's tutorial, we will talk about the modification and update of mysql views.

3. PostgreSQL 9.4 version materialized view update

Introduction: PostgreSQL version 9.4 has been out for some time , also updated a lot of content, one of which is the update of the materialized view that I am more interested in. Compared with the original materialized view syntax, new

4. Oracle inline view Problems encountered in the update

#Introduction: When I encounter a batch update requirement, I plan to use the inline view update + where in list technique to handle it.

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