11 2013 档案
PL/SQL控制结构
摘要:顺序结构 按先后顺序 分支判断结构 IF语句 IF condition THEN statements; [ELSIF condition THEN statements;] [ELSE statements;] END IF; 例: DECLARE v_myage number :=31; BEG
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多表查询
摘要:SQL1999国际标准 SELECT table1.column,table2.column From table1 [NATURAL JOIN table2]| [JOIN table2 USING (column_name)]| [JOIN table2 ON (table1.column_na
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