Case update statement sql server

Create a free Team What is Teams? Learn more. Asked 5 years, 2 months ago. Active 5 years, 2 months ago. Viewed k times. Improve this question. Bojie Shuai Bojie Shuai 43 1 1 gold badge 1 1 silver badge 6 6 bronze badges. Here's a demo of a CASE with 20 conditions working perfectly well. Yours is not a case of nested CASEs, if you pardon the pun.

The only way your normal CASE could break is if it had more than 10 conditions and was executed against a linked server, which is why Aaron has asked you about it. The issue is explained in this thread. Nested case would be like this rextester.

Please check below result screen. We have updated state code column using CASE expression. I hope that you will get an idea about how to use CASE expression. I hope you will enjoy these tips while playing with SQL Server.

In this article, I would like to show the most commonly used case expressions with update statements in SQL Server. CASE is the special scalar expression or conditional statement in the SQL language which returns a single value based on the evaluation of a statement.

In this article, you use case with an update statement. So let's have a look at a practical example of how to use a case with Update statement in SQL Server We'll start by walking through a simple case statement. A searched update modifies multiple rows when the search condition does not uniquely identify a single row.

The cursor must allow updates. Use caution when specifying the FROM clause to provide the criteria for the update operation. It is undefined which row from Table2 is to be used to update the row in Table1. Avoid using these hints in this context in new development work, and plan to modify applications that currently use them. All char and nchar columns are right-padded to the defined length. These strings are truncated to an empty string. This can be configured in ODBC data sources or by setting connection attributes or properties.

Modifying a text , ntext , or image column with UPDATE initializes the column, assigns a valid text pointer to it, and allocates at least one data page, unless the column is being updated with NULL.

If the UPDATE statement could change more than one row while updating both the clustering key and one or more text , ntext , or image columns, the partial update to these columns is executed as a full replacement of the values. Avoid using these data types in new development work, and plan to modify applications that currently use them.

Use nvarchar max , varchar max , and varbinary max instead. Use the. WRITE expression , Offset , Length clause to perform a partial or full update of varchar max , nvarchar max , and varbinary max data types. For example, a partial update of a varchar max column might delete or modify only the first bytes of the column characters if using ASCII characters , whereas a full update would delete or modify all the data in the column.

WRITE updates that insert or append new data are minimally logged if the database recovery model is set to bulk-logged or simple. Minimal logging is not used when existing values are updated. You cannot use the. Offset and Length are specified in bytes for varbinary and varchar data types and in byte-pairs for the nvarchar data type. For best performance, we recommend that data be inserted or updated in chunk sizes that are multiples of bytes. If the column modified by the.

See example R that follows. To achieve the same functionality of. Supplying a value in a SQL Server system data type, as long as the user-defined type supports implicit or explicit conversion from that type. The following example shows how to update a value in a column of user-defined type Point , by explicitly converting from a string. Invoking a method, marked as a mutator, of the user-defined type, to perform the update.

The following example invokes a mutator method of type Point named SetXY. This updates the state of the instance of the type. SQL Server returns an error if a mutator method is invoked on a Transact-SQL null value, or if a new value produced by a mutator method is null.

Modifying the value of a registered property or public data member of the user-defined type. The expression supplying the value must be implicitly convertible to the type of the property. The following example modifies the value of property X of user-defined type Point. To modify different properties of the same user-defined type column, issue multiple UPDATE statements, or invoke a mutator method of the type.

However, a large amount of data is more efficiently streamed into a file by using Win32 interfaces. You cannot use.