tailieunhanh - SQL PROGRAMMING STYLE- P39

SQL PROGRAMMING STYLE- P39:Im mot trying to teach you to program in SQL in this book. You might want to read that again. If that is what you wanted, there are better books. This ought to be the second book you buy, not the first. I assume that you already write SQL at some level and want to get better at it. If you want to learn SQL programming tricks, get a copy of my other book, SQL for Smarties (3rd edition, 2005). | Typography and Code 27 See how quickly you can find each clause reading from left to right Next if you put each clause on a line of its own you can read the code still faster SELECT a b c FROM Foobar WHERE flob 23 We will deal with rules for the vertical components later. Exceptions None Keywords come in two types reserved and nonreserved words. The reserved words are part of the SQL language the nonreserved words are metadata names that appear in the environment and will not cause syntax errors in an actual SQL program. They are also not very likely to be used in a real application. key word reserved word non-reserved word non-reserved word ADA C CATALOG_NAME CHARACTER_SET_CATALOG CHARACTER_SET_NAME CHARACTER_SET_SCHEMA CLASS_ORIGIN COBOL COLLATION_CATALOG COLLATION_NAME COLLATION_SCHEMA COLUMN_NAME COMMAND_FUNCTION COMMITTED CONDITION_NUMBER CONNECTION_NAME CONSTRAINT_CATALOG CONSTRAINT_NAME CONSTRAINT_SCHEMA CURSOR_NAME DATA DATETIME_INTERVAL_CODE DATETIME_INTERVAL_PRECISION DYNAMIC_FUNCTION FORTRAN LENGTH MESSAGE_LENGTH MESSAGE_OCTET_LENGTH MESSAGE_TEXT MORE MUMPS NAME NULLABLE NUMBER PASCAL PLI REPEATABLE RETURNED_LENGTH RETURNED_OCTET_LENGTH RETURNED_SQLSTATE 28 CHAPTER 2 FONTS PUNCTUATION AND SPACING ROW_COUNT SCALE SCHEMA_NAME SERIALIZABLE SERVER_NAME SUBCLASS_ORIGIN TABLE_NAME TYPE UNCOMMITTED UNNAMED reserved word ABSOLUTE ACTION ADD ALL ALLOCATE ALTER AND ANY ARE AS ASC ASSERTION AT AUTHORIZATION AVG BEGIN BETWEEN BIT BIT_LENGTH BOTH BY CASCADE CASCADED CASE CAST CATALOG CHAR CHARACTER CHAR_LENGTH CHARACTER_LENGTH CHECK CLOSE COALESCE COLLATE COLLATION COLUMN COMMIT CONNECT CONNECTION CONSTRAINT CONSTRAINTS CONTINUE CONVERT CORRESPONDING COUNT CREATE CROSS CURRENT CURRENT_DATE CURRENT_TIME CURRENT_TIMESTAMP CURRENT_USER CURSOR DATE DAY DEALLOCATE DEC DECIMAL DECLARE DEFAULT DEFERRABLE DEFERRED DELETE DESC DESCRIBE DESCRIPTOR DIAGNOSTICS DISCONNECT DISTINCT DOMAIN DOUBLE DROP ELSE END END-EXEC ESCAPE EXCEPT EXCEPTION EXEC EXECUTE EXISTS EXTERNAL .