||
represents string concatenation. Unfortunately, string concatenation is not completely portable across all sql dialects:
- ansi sql:
||
(infix operator) - mysql:
concat
( vararg function ). caution:||
means ‘logical or’ (It’s configurable, however; thanks to @hvd for pointing that out) - oracle:
||
(infix operator),concat
( caution: function of arity 2 only ! ) - postgres:
||
(infix operator) - sql server:
+
(infix operator),concat
( vararg function ) - sqlite:
||
(infix operator)
hopefully the confusion is complete …