参数的元数据信息&数据库的元数据信息
1 package it.cast.jdbc; 2 3 import java.sql.Connection; 4 import java.sql.DatabaseMetaData; 5 import java.sql.Date; 6 import java.sql.ParameterMetaData; 7 import java.sql.PreparedStatement; 8 import java.sql.ResultSet; 9 import java.sql.SQLException; 10 import java.sql.Statement; 11 12 public class OtherAPI { 13 14 public static void main(String[] args) throws SQLException { 15 Object[] params = new Object[] { "zero",new Date(System.currentTimeMillis()),100f }; 16 ParameterMetaTest( 17 "select * from user where name=? and birthday<? and money>? ", 18 params ); 19 } 20 21 static void read() throws SQLException { 22 Connection conn = null; 23 Statement st = null; 24 ResultSet rs = null; 25 26 try { 27 conn = jdbcUtils.getConnection(); 28 29 st = conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE, 30 ResultSet.CONCUR_UPDATABLE); 31 32 rs = st 33 .executeQuery("select id,name,money,birthday from user where id<5"); 34 35 while (rs.next()) { 36 System.out.println(rs.getObject("id") + "/t" 37 + rs.getObject("name") + "/t" 38 + rs.getObject("birthday") + "/t"); 39 40 String name = rs.getString("name"); 41 if ("lisi".equals(name)) { 42 rs.updateFloat("money", 3000f); 43 rs.updateRow(); 44 } 45 } 46 } finally { 47 jdbcUtils.free(rs, st, conn); 48 } 49 } 50 51 static void DBMD() throws SQLException { 52 Connection conn = jdbcUtils.getConnection(); 53 DatabaseMetaData dbmd = conn.getMetaData(); 54 55 System.out.println("db name:" + dbmd.getDatabaseProductName()); 56 System.out.println("tx:" + dbmd.supportsTransactions()); 57 58 conn.close(); 59 } 60 61 static void ParameterMetaTest(String sql, Object[] params) 62 throws SQLException { 63 64 Connection conn = null; 65 PreparedStatement ps = null; 66 ResultSet rs = null; 67 68 try { 69 conn = jdbcUtils.getConnection(); 70 ps = conn.prepareStatement(sql); 71 72 ParameterMetaData pmd = ps.getParameterMetaData(); 73 int count = pmd.getParameterCount(); 74 75 for (int i = 1; i <= count; i++) { 76 // System.out.println(pmd.getParameterClassName(i)+"\t"); 77 // System.out.println(pmd.getParameterType(i)+"\t"); 78 // System.out.println(pmd.getParameterTypeName(i)+"\t"); 79 ps.setObject(i, params[i - 1]); 80 } 81 rs = ps.executeQuery(); 82 while (rs.next()) { 83 System.out.println(rs.getObject("id") + "\t" 84 + rs.getObject("name") + "\t" 85 + rs.getObject("birthday") + "\t"); 86 } 87 88 } finally { 89 jdbcUtils.free(rs, ps, conn); 90 } 91 } 92 93 }
1 package it.cast.jdbc; 2 3 import java.sql.CallableStatement; 4 import java.sql.Connection; 5 import java.sql.DriverManager; 6 import java.sql.PreparedStatement; 7 import java.sql.ResultSet; 8 import java.sql.SQLException; 9 import java.sql.Statement; 10 11 public class jdbcUtils { 12 13 private static String url = "jdbc:mysql://localhost:3306/jdbc?generateSimpleParameterMetadata=true"; 14 private static String user = "root"; 15 private static String password = "123"; 16 17 private jdbcUtils() { 18 19 } 20 21 static { 22 try { 23 Class.forName("com.mysql.jdbc.Driver"); 24 } catch (ClassNotFoundException e) { 25 e.printStackTrace(); 26 } 27 } 28 29 public static Connection getConnection() throws SQLException { 30 return DriverManager.getConnection(url, user, password); 31 } 32 33 public static void free(ResultSet rs, Statement st, Connection conn) { 34 35 try { 36 if (rs != null) 37 rs.close(); 38 } catch (SQLException e) { 39 e.printStackTrace(); 40 } finally { 41 42 try { 43 if (st != null) 44 st.close(); 45 } catch (SQLException e) { 46 e.printStackTrace(); 47 } finally { 48 49 try { 50 if (conn != null) 51 conn.close(); 52 } catch (SQLException e) { 53 e.printStackTrace(); 54 } 55 } 56 57 } 58 59 } 60 61 public static void free(ResultSet rs, PreparedStatement ps, Connection conn) { 62 63 try { 64 if (rs != null) 65 rs.close(); 66 } catch (SQLException e) { 67 e.printStackTrace(); 68 } finally { 69 70 try { 71 if (ps != null) 72 ps.close(); 73 } catch (SQLException e) { 74 e.printStackTrace(); 75 } finally { 76 77 try { 78 if (conn != null) 79 conn.close(); 80 } catch (SQLException e) { 81 e.printStackTrace(); 82 } 83 } 84 85 } 86 87 } 88 public static void free(ResultSet rs, CallableStatement cs, Connection conn) { 89 90 try { 91 if (rs != null) 92 rs.close(); 93 } catch (SQLException e) { 94 e.printStackTrace(); 95 } finally { 96 97 try { 98 if (cs != null) 99 cs.close(); 100 } catch (SQLException e) { 101 e.printStackTrace(); 102 } finally { 103 104 try { 105 if (conn != null) 106 conn.close(); 107 } catch (SQLException e) { 108 e.printStackTrace(); 109 } 110 } 111 112 } 113 114 } 115 }
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