Create temporary table insert into mysql11/28/2023 If your application is conservative and your data volumes light you’ll never want anything else. The downside of table variables is that they are often disposed of before you can investigate their contents for debugging, or use them to try out different SQL expressions interactively. Transaction rollbacks do not affect them because table variables have limited scope and are not part of the persistent database, so they are handy for creating or storing data that ought to survive roll backs such as log entries. Table variables require less locking resources as they are ‘private’ to the process that created them. These are much easier to work with, and pretty secure, and they also trigger fewer recompiles in the routines where they’re used than if you were to use temporary tables. They behave like other variables in their scoping rules. However, they are good for many of the uses that the traditional temporary table was put to. Table variables are used within the scope of the routine or batch within which they are defined, and were originally created to make table-valued functions possible. Just occasionally, you may need to fine-tune them to get good performance from them in joins, but I’ll explain that in a moment, However, if you are doing more complex processing on temporary data or likely to use more than reasonably small amounts of data in them, then local temporary tables are likely to be a better choice. They also tend to cause fewer problems to a hard-working OLTP system. They’re easy, and SQL Server does the work for you. Temporary tables come in different flavours including, amongst others, local temporary tables (starting with #), global temporary tables (starting with #), persistent temporary tables (prefixed by TempDB.), and table variables.(starting with we get too deep into the technology, I’d advise that you should use table variables where possible. Once finished with their use, they are discarded automatically. They are also used to pass a table from a table-valued function, to pass table-based data between stored procedures or, more recently in the form of Table-valued parameters, to send whole read-only tables from applications to SQL Server routines, or pass read-only temporary tables as parameters. They are used most often to provide workspace for the intermediate results when processing data within a batch or procedure. Is the only other option to create it manually from the information schema? That really feels like using a sledgehammer to crack a walnut, surely there must be a simpler way to do it? Not too mention a lot of work.Temporary tables in SQL Server are just that. a VARCHAR column will only be defined according to the max length of the column in the select statement) and b) I don't want to copy all 4 million rows simply to truncate them in the next statement! If you do that it a) only creates the column definitions to fit the data in the select (i.e. CREATE TEMPORARY TABLE myTable SELECT * from source.myTable I can't do the alternative which would be to do. MySQL can't create temp tables with partitions. Which works fine, apart from one table which is partitioned. To create a copy I used the SQL CREATE TEMPORARY TABLE myTable LIKE source.myTable In one of my reporting scripts, it creates a temporary copy of a table before inserting some rows in order to a bulk update on the source table. I've got a little issue and wonder if anyone has come across it themselves or seen a solution.
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