What is dynamic query in SQL Server with example?
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What is dynamic query in SQL Server with example?
Dynamic SQL is the SQL statement that is constructed and executed at runtime based on input parameters passed. Let us go through some examples using the EXEC command and sp_executesql extended stored procedure.
What is a dynamic query?
Dynamic queries refer to queries that are built dynamically by Drupal rather than provided as an explicit query string. All Insert, Update, Delete, and Merge queries must be dynamic. Select queries may be either static or dynamic. Therefore, “dynamic query” generally refers to a dynamic Select query.
What is the difference between static and dynamic query?
Dynamic SQL is SQL statements that are constructed at runtime; for example, the application may allow users to enter their own queries….Difference between Static and Dynamic SQL.
| Static (Embedded) SQL | Dynamic (Interactive) SQL |
|---|---|
| SQL statements are compiled at compile time. | SQL statements are compiled at run time. |
What is the use of Sp_executesql?
sp_executesql can be used instead of stored procedures to execute a Transact-SQL statement many times when the change in parameter values to the statement is the only variation.
How do I use dynamic SQL?
Steps to use Dynamic SQL :
- Declare two variables, @var1 for holding the name of the table and @var 2 for holding the dynamic SQL : DECLARE @var1 NVARCHAR(MAX), @var2 NVARCHAR(MAX);
- Set the value of the @var1 variable to table_name : SET @var1 = N’table_name’;
How do you remove duplicate records from a table?
It can be done by many ways in sql server the most simplest way to do so is: Insert the distinct rows from the duplicate rows table to new temporary table. Then delete all the data from duplicate rows table then insert all data from temporary table which has no duplicates as shown below.
What is meant by Alias in SQL?
Aliases are the temporary names given to table or column for the purpose of a particular SQL query. It is used when name of column or table is used other than their original names, but the modified name is only temporary. Aliases are created to make table or column names more readable.
What is dynamic SQL in MySQL?
MySQL supports Dynamic SQL with the help of EXECUTE and PREPARE statements. Suppose you have a scenario where you need to pass table name as parameter value and returns all column values, you can use Dynamic SQL. DEALLOCATE PREPARE dynamic_statement; The variable @table_name is assigned name of the table.
What is difference between exec and Sp_executesql?
sp_executesql supports parameterisation, whereas EXEC only accepts a string. Only performance differences that may arise are due to the parameterisation i.e. a parameterised sp_executesql call is more likely to have a reusable cached plan.
What is the syntax of dynamic query?
Syntax for dynamic SQL is to make it string as below : ‘SELECT statement’; To run a dynamic SQL statement, run the stored procedure sp_executesql as shown below : EXEC sp_executesql N’SELECT statement’;