Data type precedence (Transact-SQL)

Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance Azure Synapse Analytics Analytics Platform System (PDW) SQL analytics endpoint in Microsoft Fabric Warehouse in Microsoft Fabric SQL database in Microsoft Fabric

When an operator combines expressions of different data types, the data type with the lower precedence is first converted to the data type with the higher precedence. If the conversion isn't a supported implicit conversion, an error is returned. For an operator combining operand expressions having the same data type, the result of the operation has that data type.

SQL Server uses the following precedence order for data types:

1. user-defined data types (highest)
2. json
3. sql_variant
4. xml
5. datetimeoffset
6. datetime2
7. datetime
8. smalldatetime
9. date
10. time
11. float
12. real
13. decimal
14. money
15. smallmoney
16. bigint
17. int
18. smallint
19. tinyint
20. bit
21. ntext
22. text
23. image
24. timestamp
25. uniqueidentifier
26. nvarchar, including nvarchar(max)
27. nchar
28. varchar, including varchar(max)
29. char
30. varbinary, including varbinary(max)
31. binary (lowest)

• Data types (Transact-SQL)
• Expressions (Transact-SQL)
• CAST and CONVERT (Transact-SQL)