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SQL UPDATE Statement

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The SQL UPDATE Statement is used to update the existing records with new data. Before we get into the practical example, let us see the syntax behind this SQL server update.

SQL UPDATE Statement Syntax

The basic syntax of the SQL Server update statement is as shown below:

-- SQL Server UPDATE Syntax
UPDATE [Table] 
SET [Column1] = [Value1], 
    [Column2] = [Value2],
    [ColumnN] = [ValueN]
WHERE Condition
  • Table: Please provide the fully qualifies Table name on which you want to perform update operations (updating records)
  • Column1…ColumnN: Please select the column names on which you want to update. It may be One or more.
  • Value1…ValueN: Please specify the values that you want to update.
  • Condition: Here we have to provide the filters or conditions. If the condition is TRUE then only UPDATE Statement will update the records.

In this article we will show you, How to write UPDATE query in SQL Server. From the below screenshot you can observe that, We have [SQL Update] table in [SQL Tutorial] and it holds 14 records. Here, we are going to perform the different types of update operations on this table

SQL UPDATE Statement 1

SQL UPDATE Statement

In this example, We are going to update the Yearly Income of all the Employees in [SQL Update] Table.

-- Example for SQL Server Update Statement
UPDATE [SQL Update]
SET [YearlyIncome] = 100000

OUTPUT

SQL UPDATE Statement 2

NOTE: Here, we haven’t specified any WHERE condition, that’s why SQL server updated all the 14 records. This is the most dangerous approach in real-time environment because if you forgot the where clause means you are ruing the client data.

SQL UPDATE Statement – Updating Single record

In this example, We are going to update one single record in [SQL Update] Table.

-- Example for Update Query in SQL Server
UPDATE [SQL Update]
SET [YearlyIncome] = 250000
WHERE [Id] = 5

OUTPUT

From the below screenshot you can observe that, it is updating the [yearly Income] with 250000 for the records whose ID value = 5

SQL UPDATE Statement 3

SQL UPDATE Statement – Updating Multiple records

In this example, We are going to update multiple record into [SQL Update] Table.

-- Example for Update Query in SQL Server
UPDATE [SQL Update]
SET [YearlyIncome] = 123456,
    [Sales] = 4500
WHERE [Occupation] = 'Professional'

OUTPUT

From the below screenshot you can observe that, it is updating the [yearly Income] with 123456 and sale as 4500 for all the records whose Occupation is Professional

SQL UPDATE Statement 4

SQL UPDATE Statement – Updating New values

Suppose the government has increased some Tax values to 0.5% for all Goods and Services (or any particular Good) then we can use this SQL Server Update statement to update those values with new one. OR you want to increase your goods prices then you can use it.

-- Example for Update Query in SQL Server
UPDATE [SQL Update]
SET [Sales] = [Sales] * 2

OUTPUT

SQL UPDATE Statement 5

SQL Server UPDATE Statement – Updating records from other table

In this example, We are going to update the record in [SQL Update] Table with the new values in [SQL Update] Table.

-- Example for Update Query in SQL Server
UPDATE [SQL Update]
SET [YearlyIncome] = ( 
			SELECT [YearlyIncome] FROM [SQL Updates]
			WHERE [SQL Update].[FirstName] = [SQL Updates].[FirstName]
			AND 
			[SQL Update].[LastName] = [SQL Updates].[LastName])

OUTPUT

SQL UPDATE Statement 6

ANALYSIS

Below code will retrieve all the records from Yealy Income column in [SQL Updates] Table

SELECT [YearlyIncome] FROM [SQL Updates]

Placed Under: SQL