Expression Syntax

This sections describes Skyvia expression syntax which is used in expression mapping of data integration packages using the new runtime as well as data flow packages. Packages, using old runtime, use SSIS expression syntax. You can find more information about main syntax differences in the Main Differences between Old and New Runtime Syntax topic.


Identifiers in our expression syntax are source column names. If an identifier does not coincide with any keywords, data types, or functions, consists only of English letters, numbers, or an underscore, and starts with an English letter or an underscore, you can use it without additional qualifiers. Otherwise, an identifier must be delimited by double quotation marks. Identifiers are case-sensitive.

Skyvia allows loading data from multiple related tables/objects in the same tasks. In import, you can select relations of the main source objects in order to add data of related tables/objects to import. Synchronization also allows many-to-one and one-to-many synchronization. In this case, if you want to use columns of a related table/object in expression, you need to add it as the relation name, followed by the column name, separated by a dot character. If the relation name or column name need to be delimited by quotes, delimit them separately. For example "My foreign key"."My column".

Data Types

Skyvia expressions support the following data types:

  • Boolean type: bool
  • Integer types: int1, int2, int4, int8
  • Floating point types: float4, float8
  • Fixed precision type: decimal
  • Date/time types: datetime, datetimeoffset, time
  • String type: _string
  • Other types: bytes, guid

For information about data type conversion, see the Data Types and Type Conversion topic.


Skyvia expressions can include numeric, string, and boolean literals. Read the Literals topic for the information about how to enter literals and constant values of different types in your expressions.


Skyvia supports various mathematical, logical, and comparison operators, and conditional operator ? :. You can find the complete list of operators as well as their precedence in the Operators topic.


You can use a wide range of mathematical, string, datetime, and other functions. See the complete list of supported functions in the Functions topic.