1 CAST ( source_expression AS
2 BIT
2 BLOB
2 BOOLEAN
2 CHAR
2 CHARACTER
2 DATE
2 DECIMAL
2.1? ( precision , scale )
2 FLOAT
2 GMTTIME
2 GMTTIMESTAMP
2 INT
2 INTEGER
2 INTERVAL  interval_qualifier
2 TIME
2 TIMESTAMP
3? 
3 CCSID ccsid_expression
4? 
4 ENCODING encoding_expression
5 )