Coalesce

COALESCE is a SQL function that returns the first non-NULL expression among its arguments

Isnull

`ISNULL` is a SQL function that replaces NULL with the specified replacement value.



Query plans names

Example

"To prefer isnull over coalesce when given the choice is that isnull tends to produce query plans that are more efficient than coalesce"

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Which is quicker COALESCE OR ISNULL?

"If all names match if they don t then use isnull or coalesce but isnull is more efficient"

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SQL Server Update sub query with formula not quite right

Faster first values

Example

"The function isnull is kind of equivalent but coalesce allows more arguments and is standard sql."

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When or why is equals not the opposite of not equals in a SQL query?

"This question suggests that there is very little difference between isnull and coalesce"

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What is the performance impact with using IS NULL OR vs. ISNULL with LIKE?

"I tend to use coalesce only when i need to get the first non-null value from a set of 3 or more values as isnull only supports two parameters"

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Sort query by field related to another field

"Also note that isnull is faster than coalesce even if the difference is pretty negligible"

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How to check a column values is null or not in select statement

"Regarding isnull vs coalesce -;it seems that isnull is faster in this instance"

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Computed column function that references another row?

"Coalesce -- although standard -- has the downfall that it evaluates the first argument twice;so when the first argument is non-trivial isnull is the better approach in sql server"

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Better way to filter out SQL data error on large table

"However coalesce evaluates the first argument twice;so for an expensive operation such as a user-defined function isnull is more efficient"

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Set zero default value for null rows in SQL Server

"Isnull will be faster i think because it has lesser function code implementation for itself making it faster than coalesce"

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Which is quicker COALESCE OR ISNULL?

"Isnull can only have one input however it s been shown to be slightly faster than coalesce"

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SQL - Difference between COALESCE and ISNULL?

"Isnull is marginally faster than coalesce"

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Why IsNull is twice slow as coalesce (same query)?

"This is pretty much the ifloop answer but isnull is slightly faster than coalesce"

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Best way to do a CASE where clause SQL Server

"Isnull is faster than coalesce"

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SQL - Difference between COALESCE and ISNULL?

"In some circumstances isnull is faster than case or coalesce"

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Coalesce vs Case

"You can use isnull also in place of coalesce as isnull is comparatively faster than coalesce"

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SQL increment integer column even if null

"I understand the difference between these functions but my question is when checking for a single null value would isnull be any quicker than using coalesce"

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Which is quicker COALESCE OR ISNULL?

"Coalesce will go through the listed values and choose the first one that isn t null it s more portable code than isnull or ivnl etc"

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How to insert an alternative value from an old table into a new table IF NULL.

Better sql server

Example

"In most cases it has reviled indexes that needed to be add and in most cases the indexes improved the queries the most but after thet have been added the isnull and dynamic still perform better than the coalesce"

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SQL Where clause Coalese vs ISNULL VS Dynamic

"On the subject of performance on sql server isnull often performs better than coalesce but the latter is ansi compliant if that is important to you"

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Boolean equivalence

"Isnull is better then coalesce because of how datatypes are handled"

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Question regarding index

"You will find that coalesce works better than isnull here"

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SQL Join on multiple OR conditions returns duplicates

"Is the performance of coalesce field constant better than isnull"

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Performance of ISNULL and COALESCE with a constant as second value

"An example of why coalesce is better than isnull"

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Select rows WHERE column = value or column is null (current solution is sloppy and slow)

"Isnull performs better than the generic coalesce and better than having another and"

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SQL Query Date between, if date column not null

"But depending on the answers to those questions i m guessing that coalesce might do the trick for you better than isnull"

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SQL like Clause (null and blank values)

"Edit based on the tests done by multiple people and by theory isnull seems to be a better option over coalesce"

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Substitute FROM ISNULL in where clause in ms sql server

"The most natural function to use is coalesce because it is the ansi-standard function for this purpose;under some circumstances in sql server isnull has better performance but this is not one of those circumstances"

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How to Convert (null) values with 0 output in PIVOT SQL

"You also are missing the on clause on your first join a full join is not necessary as a left join to your catalog table covers what you need coalesce is sql iso standard but as you are comparing only two values and you are using sql server isnull is better to perform that operation use two left joins or you can use union all"

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How to sum values from three unrelated tables

"Isnull and coalesce do just about the same thing but isnull is t-sql while coalesce is more generic"

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How to pad "x" to the end of a string of fixed length

"In such cases coalesce is better choice;below is an example showing the difference between isnull and coalesce"

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SQL Server how to set a default value when the column is null

"Note that in this case the isnull would do the same as coalesce but looks better for this application in case you add some new language"

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SQL Server language data in table

"The generic sql solution uses coalesce in sql server isnull is a better choice for performance reasons"

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Sum two tables value and show value if one column is null

Important flexible isnull

Example

"The coalesce is ansi standard and isnull is not;but more important is the fact that coalesce is more flexible"

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SQL: sum 3 columns when one column has a null value?

"But more important is the fact that coalesce is more flexible;isnull will only work with two parameters"

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SQL: sum 3 columns when one column has a null value?

Others

Example

Coalesce is the more standard alternative of isnull

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Using MS SQL ISNULL() with Alias

Coalesce is more correct of course you could just embed isnull over and over and over.. but put that under a performance microscope and coalesce may just win

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IsNULL and Coalesce proper usage

Sql server is probably smart enough to translate isnull into the equivalent sarg expression but if you are bent on using a function then coalesce is a better choice because it is part of the sql standard allows for multiple values instead of just two with isnull and avoids using quite possibly the most confusing function name microsoft ever devised in isnull

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Sargable queries using ISNULL in TSQL

Coalesce function works a bit different coalesce will take any number of parameters and return the first non- null value i prefer coalesce over isnull cause;meets ansi standarts while isnull does not

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IsNULL and Coalesce proper usage

Coalesce is more cross-compatible than isnull or nvl it works on mssql oracle mysql derby et al.

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SQL LEFT JOIN return 0 rather than NULL

You can also use coalesce which is the more general form of isnull and is actually part of the sql standard

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C# ADO.NET - return sum of one columns in table

In this case i would use coalesce which provides more levels than isnull rather than the case stement

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COALESCE or CASE more efficient and/or standard

- coalesce should be more portable than isnull

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Incompatible SQL trigger

Using coalesce is better option than isnull or case..when for this problem since the input values for the coalesce expression can be evaluated multiple times

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Syntax error when assigning column value using CASE WHEN in Computed Column Formula

I ve been told that coalesce is less costly than isnull but research doesn t indicate that

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COALESCE Function in TSQL

However i prefer isnull over coalesce since the latter has an issue if it contains a sub-query

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Should i use IIF and ISNULL to select a default-value?

One of the many reasons why you should generally prefer coalesce over isnull 1

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Why my dynamic query returns NUL instead of NULL in SQL server?

Use coalesce instead;it functions much like isnull although provides more functionality

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What is the PostgreSQL equivalent for ISNULL()

Dbfiddle demo isnull infers data type from first argument coalesce infers from wider one data type precedence

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ISNULL prints *

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