java - how to concat sql query using union operator -

java - how to concat sql query using union operator -

string query="select * recommendation.sports feed like'%"+s1+"%' union "select * recommendation.software feed '%"+s1+"%' union "select * recommendation.website feed '%"+s1+"%' union "select * recommendation.others feed '%"+s1+"%' union "select * recommendation.business feed '%"+s1+"%'";

maybe mean this?

string query = "select * recommendation.sports feed '%" + s1 + "%' " + "union " + "select * recommendation.software feed '%" +s1+ "%' " + "union " + "select * recommendation.website feed '%" +s1+" %' " + "union " + "select * recommendation.others feed '%"+s1+"%' " + "union " + "select * recommendation.business feed '%" +s1+ "%'" ;

but advise utilize preparedstatements on query avoid sql injection.

string query = "select * recommendation.sports feed concat('%', ?, '%') " + "union " + "select * recommendation.software feed concat('%', ?, '%') " + "union " + "select * recommendation.website feed concat('%', ?, '%') " + "union " + "select * recommendation.others feed concat('%', ?, '%') " + "union " + "select * recommendation.business feed concat('%', ?, '%')" ; preparedstatement pstmt = con.preparestatement(query); pstmt.setstring(1, s1); pstmt.setstring(2, s1); pstmt.setstring(3, s1); pstmt.setstring(4, s1); pstmt.setstring(5, s1); resultset _result = pstmt.executequery(); java preparedstatement

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