Oracle multiple processes updating same table dating my sister
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.
That’s a terrible way to update data, but for various reasons, I’m sure many readers have found themselves in a similar situation.
If the largest possible key has previously existed in that table, then the INSERT will fail with an SQLITE_FULL error code. The datatype you assign to a column in the CREATE TABLE command does not restrict what data can be put into that column.
Every column is able to hold an arbitrary length string.
works fine when I try to update all the records in tbl A, however, in this case I only have missing data which I have identified and populated in tbl B.
When I try to update only the missing data the non-matched data is also updated but to NULL. The reason some of your rows are getting NULLs updated is due to the subquery.
Note that the integer key is one greater than the largest key that was in the table just prior to the insert.
The new key will be unique over all keys currently in the table, but it might overlap with keys that have been previously deleted from the table.
I have to start with one spreadsheet, then insert and/or update the differences from the others.This is typically the case when you have to synchronize a table periodically with data from another source (table/view/query).In place of 3 separate unwieldy INSERT, UPDATE and DELETE statements with conditional sub-queries, the all-in-one MERGE does the job in one shot.Oracle’s MERGE statement is tailor-made for situations when you want to do an "upsert" i.e.update existing rows in a table or insert new rows depending on a match condition.