|
|
|
If expr is NULL, then value is returned; otherwise the result of expr is returned. See COALESCE for evaluating multiple expressions.
|
|
|
|
|
|
If expr1 is not Null, then it is returned; otherwise, expr2 is evaluated and, if not Null, it is returned, and so on. This is an ANSISQL standard system function.
|
|
If value1 equals value2, then Null is returned; otherwise, value1 is returned.
|
CASE value1 WHEN value2 THEN value3 [ELSE value4] END
|
When value1 equals value2, then value3 is returned; otherwise, value4 or Null is returned in the absence of ELSE.
|
CASE WHEN expr1 THEN value1 [WHEN expr2 THEN value2] [ELSE value4] END
|
When expr1 is true, then value1 is returned (optionally repeated for more cases); otherwise value4 or Null is returned in the absence of ELSE.
|
|
|
POSITION(string_expression1 IN string_expression2)
|
If string_expression1 is a sub-string of string_expression2, then the position of the sub-string, counting from one, is returned; otherwise, 0 is returned.
|
SUBSTRING(string_expression FROM numeric_expression1 [FOR numeric_expression2])
|
string_expression is returned from the numeric_expression1 starting location. Optionally, numeric_expression2 specifies the length of the substring.
|
|
|