How to use temp table in Sybase?
To create a temporary table, you must have create table permission in tempdb. create table permission defaults to the database owner. Adaptive Server does not change the names of temporary tables created this way. The table exists until the current session ends or until its owner drops it using drop table.
To create Local Temporary Table, a single “#” is used as the prefix of a table name. To manually drop this temporary table by using the “DROP TABLE #temp-table” query. There will be Random Numbers are appended to the Name of Table Name.
Global Temporary Table: To create a Global Temporary Table, add the “##” symbol before the table name. Global Temporary Tables are visible to all connections and Dropped when the last connection referencing the table is closed. Global Table Name must have an Unique Table Name.
We can create a local temporary table by using # before the table name. They are available only for the current user session. They get discarded automatically once the session has ended.
After creating the temporary table, we can populate and query it. Global table names are not transformed into a unique name. Global temporary tables can be dropped explicitly with the DROP TABLE statement on any connection or automatically dropped when the session is closed that creates the table.
To insert the result of a SELECT statement into a temporary table in SQL, you can use the CREATE TEMPORARY TABLE and INSERT INTO statements. The CREATE TEMPORARY TABLE statement creates a temporary table with a given name and structure, and the INSERT INTO statement inserts rows into the table.
- create table TestTable(id int) ...
- create table #TestTable(id int) ...
- select * from tempdb.sys.tables where name like '#TestTable%'
- select object_id('tempdb..#TestTable','U')
- if object_id('tempdb..#TestTable','U') is not null.
To create a temporary table, you must have create table permission in tempdb. create table permission defaults to the database owner. Adaptive Server does not change the names of temporary tables created this way. The table exists until the current session ends or until its owner drops it using drop table.
Temporary tables storage engine
The temporary table is created in-memory or on-disk, depending on the configuration, and it's dropped immediately at the end of the query. From MySQL 5.7, they are created as InnoDB by default.
In SQL Server, to use a temp table within a stored procedure, first, we need to create a temp table and then perform the required operation. This is because a temp table in SQL Server is bound to the current session. And once the session end, the temp table is automatically deleted (dropped).
How to insert data temp table in SQL?
Create a Global Temporary Table in SQL Server. You can also create a global temporary table by placing double hash (##) before the temporary table name. The global temporary table will be available across different connections. 3 records will be inserted into the table.
Using SQL Select Statement
SELECT column_list INTO #temporary_table_name FROM TABLE_NAME WHERE conditional_expression; We use the select statement followed by the name of the temporary table. The name of a temp table in SQL Server starts with a # sign.
- SELECT QUOTENAME([name]) + ',' as ColumnName,
- TYPE_NAME(user_type_id) as DataTypeName, *
- FROM tempdb.sys.columns.
- WHERE OBJECT_ID = OBJECT_ID('tempdb.. #tmp_table');
A valuable alternatives for the SQL temp table and table variable are SCHEMA_ONLY Memory-Optimized tables and the Memory-optimized Table Variable, where the data will be completely stored in the memory without the need to touch the TempDB database, providing the best data access performance.
Temporary tables can have a Time Travel retention period of 1 day; however, a temporary table is purged once the session (in which the table was created) ends so the actual retention period is for 24 hours or the remainder of the session, whichever is shorter.
You can get that from the system views and DMVs in tempdb. For example, select from tempdb. sys. columns to get column and datatype data about temp tables.
This all means that temporary tables behave like any other sort of base table in that they are logged, and stored just like them. In practice, temporary tables are likely to remain cached in memory, but only if they are frequently-used: same as with a base table.
- CREATE TABLE #Mytemp(Col1 nvarchar(100), Col2 int) SQL. Copy.
- CREATE TABLE #tmp(ID INT IDENTITY(1,1), Col1 nvarchar(100), Col2 int) SQL. Copy.
- ALTER TABLE #Temp ADD AutoID INT IDENTITY(1,1); SQL. Copy.
- In SQL Server Management Studio, connect to an instance of the SQL Server Database Engine.
- Expand Databases.
- Right-click a database.
- Select Tasks.
- Choose to Import Data or Export Data:
Temporary tables are stored in TempDB. They work like a regular table in that you can perform the operations select, insert and delete as for a regular table. If created inside a stored procedure, they are destroyed upon completion of the stored procedure.
What is the difference between a view and a temp table?
A view exists only for a single query. Each time you use the name of a view, its table is recreated from existing data. A temporary table exists for the entire database session in which it was created. A view is automatically populated with the data retrieved by the query that defines it.
Temporary tables are allowed CREATE INDEXes whereas, Table variables aren't allowed CREATE INDEX instead they can have an index by using Primary Key or Unique Constraint. A table variable can be passed as a parameter to functions and stored procedures while the same cannot be done with Temporary tables.
- select * INTO #TEMPTABLE from DataMasterView.
- select * from #TEMPTABLE.
- drop table #TEMPTABLE.
- -- Variable Declaration. DECLARE @id INT. DECLARE @BookName VARCHAR(MAX) DECLARE @BookNumber VARCHAR(MAX) ...
- DECLARE @Nextid INT. DECLARE @NextBookName VARCHAR(MAX) DECLARE @NextBookNumber VARCHAR(MAX) ...
- -- DECLARE @MatchTemp TABLE( Id int,
The use of temporary tables, or temp tables in SQL terms, is common in SQL, but once we're done with those tables, they should be deleted, or dropped. Using the DROP TABLE command on a temporary table, as with any table, will delete the table and remove all data.