Each data store supports a number of SQL expressions. An expression is a combination of one or more values, operators, and SQL functions that evaluate to a value. You can use expressions in the Where, Having, and Order By clauses of Select statements; and in the Set clauses of Update statements.
Expressions enable you to use mathematical operations as well as character string manipulation operators to form complex queries.
Hybrid Data Pipeline supports both unquoted and quoted identifiers. An unquoted identifier must start with an ASCII alpha character and can be followed by zero or more ASCII alphanumeric characters. Unquoted identifiers are converted to uppercase before being used.
Quoted identifiers must be enclosed in double quotation marks (""). A quoted identifier can contain any Unicode character including the space character. The Hybrid Data Pipeline service recognizes the Unicode escape sequence \uxxxx as a Unicode character. You can specify a double quotation mark in a quoted identifier by escaping it with a double quotation mark.
The maximum length of both quoted and unquoted identifiers is 128 characters.
Valid expression elements are:
Column names: The most common expression is a simple column name. You can combine a column name with other expression elements.
Literals: Literals are fixed data values. See Literals for more information.
Operators: An operator manipulates individual data items and returns a result. See Operators for more information.
Functions: Hybrid Data Pipeline supports a number of functions that you may use in expressions, as listed and described in the Supported scalar functions section.
Conditions: A condition specifies a combination of one or more expressions and logical operators that evaluates to either TRUE, FALSE, or UNKNOWN. See Conditions for more information.
Column names: The most common expression is a simple column name. You can combine a column name with other expression elements.
