存储过程-更新和插入

Question

I'm new to using stored procedures, what is the best way to update and insert using stored procedures. I have two tables and I can match them by a distinct ID, I want to update if the ID exists in both my load table and my destination table, and I want to insert if the item does not exist in my destination table. Just an example template would be very helpful, thanks!

Answer 1

You should look up the SQL MERGE statement.

It allows you to perform UPSERT's - ie INSERT if a key value does not already exist, UPDATE if the key does exist.

http://technet.microsoft.com/en-us/library/bb510625.aspx

However, your requirement to check for a key value in 2 places before you perform an update does make it more complex. I haven't tried this but I would think a VIEW or a CTE could be used to establish if the ID exists in both your tables & then base the MERGE on the CTE/VIEW.

But definitely start by looking at MERGE!

Answer 2

If I understood well, you want to select values in one table and insert them in other table. If the id exists in the second table, you need to update the row. If I'm not wrong you need something like this:

mysql> select * from table_1;
+----+-----------+-----------+
| id | name      | last_name |
+----+-----------+-----------+
|  1 | fagace    | acero     |
|  2 | ratangelo | saleh     |
|  3 | hectorino | josefino  |
+----+-----------+-----------+
3 rows in set (0.00 sec)

mysql> select * from table_2;
+----+-----------+-----------+
| id | name      | last_name |
+----+-----------+-----------+
|  1 | fagace    | acero     |
|  2 | ratangelo | saleh     |
+----+-----------+-----------+
2 rows in set (0.00 sec)

mysql> insert into table_2 select t1.id,t1.name,t1.last_name from table_1 t1 on duplicate key update name=t1.name, last_name=t1.last_name;
Query OK, 1 row affected (0.00 sec)
Records: 3  Duplicates: 0  Warnings: 0

mysql> select * from table_2;
+----+-----------+-----------+
| id | name      | last_name |
+----+-----------+-----------+
|  1 | fagace    | acero     |
|  2 | ratangelo | saleh     |
|  3 | hectorino | josefino  |
+----+-----------+-----------+
3 rows in set (0.00 sec)

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