mybatis-sql builder class

在拼接sql的時候，常常遇到字符串寫的太長沒法辨別的狀況

 

String sql = "SELECT P.ID, P.USERNAME, P.PASSWORD, P.FULL_NAME, " "P.LAST_NAME,P.CREATED_ON, P.UPDATED_ON " + "FROM PERSON P, ACCOUNT A " + "INNER JOIN DEPARTMENT D on D.ID = P.DEPARTMENT_ID " + "INNER JOIN COMPANY C on D.COMPANY_ID = C.ID " + "WHERE (P.ID = A.ID AND P.FIRST_NAME like ?) " + "OR (P.LAST_NAME like ?) " + "GROUP BY P.ID " + "HAVING (P.LAST_NAME like ?) " + "OR (P.FIRST_NAME like ?) " + "ORDER BY P.ID, P.FULL_NAME";

 

mybatis3中經過SQLclass使得代碼更整潔

private String selectPersonSql() { return new SQL() {{ SELECT("P.ID, P.USERNAME, P.PASSWORD, P.FULL_NAME"); SELECT("P.LAST_NAME, P.CREATED_ON, P.UPDATED_ON"); FROM("PERSON P"); FROM("ACCOUNT A"); INNER_JOIN("DEPARTMENT D on D.ID = P.DEPARTMENT_ID"); INNER_JOIN("COMPANY C on D.COMPANY_ID = C.ID"); WHERE("P.ID = A.ID"); WHERE("P.FIRST_NAME like ?"); OR(); WHERE("P.LAST_NAME like ?"); GROUP_BY("P.ID"); HAVING("P.LAST_NAME like ?"); OR(); HAVING("P.FIRST_NAME like ?"); ORDER_BY("P.ID"); ORDER_BY("P.FULL_NAME"); }}.toString(); }

 

這種提供的方法不用擔憂where是否重複,and是否會多的問題