The object of java.sql.ResultSetMetaData can be used to get the details of the columns available in the ResultSet object.
Some of the important methods of ResultSetMetaData are
|
1 2 3 4 5 6 |
1. getColumnCount() 2. getColumnDisplaySize(int column) 3. getColumnLabel(int column) 4. getColumnName(int column) 5. getColumnType(int column) 6. getColumnTypeName(int column) |
Lets see ResultSetMetaData in JDBC example using some of the above methods
ResultSetMetaData in JDBC example
Details of the Database table
|
1 2 3 4 5 6 7 |
CREATE TABLE employee_details( id int(5) not null, first_name varchar(255), last_name varchar(255), designation varchar(255), salary int(5) ) |
Now we will write a sample code that will get the details of each of the columns using ResultSetMetaData
Please Note : Column number starts from 1. So when you use getColumnName(int column) or any other method, the parameter should start from 1 (and not 0). See the for loop in the sample code starts with int i = 1
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 |
package com.kscodes.sampleproject.jdbc; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.ResultSetMetaData; import java.sql.SQLException; import java.sql.Statement; public class ResultSetMetaDataExample { public static String DRIVER_CLASS_NAME = "com.mysql.jdbc.Driver"; public static String CONNECTION_URL = "jdbc:mysql://localhost:3306/mysql"; public static String CONNECTION_USER = "kscodes"; public static String CONNECTION_PASSWORD = "kscodes"; public static void main(String[] args) { String selectSql = "SELECT * FROM employee_details"; try (Connection connection = getConnection(); Statement statement = connection.createStatement()) { ResultSet rs = statement.executeQuery(selectSql); ResultSetMetaData resultSetMetaData = rs.getMetaData(); int columnCount = resultSetMetaData.getColumnCount(); System.out.println("Total Number of Columns are :: " + columnCount); for (int i = 1; i <= columnCount; i++) { String columnName = resultSetMetaData.getColumnName(i); int columnType = resultSetMetaData.getColumnType(i); String columnTypeName = resultSetMetaData.getColumnTypeName(i); System.out.println("Column Name ::" + columnName); System.out.println("Column Type ::" + columnType); System.out.println("Column Type Name ::" + columnTypeName); System.out.println("-------------------------------"); } } catch (SQLException e) { System.out.println("An exception occured while Selecting records from Table. Exception is :: " + e); } } public static Connection getConnection() { try { Class.forName(DRIVER_CLASS_NAME); } catch (ClassNotFoundException e) { System.out.println("Error while registering JDBC driver"); return null; } Connection connection = null; try { connection = DriverManager.getConnection(CONNECTION_URL, CONNECTION_USER, CONNECTION_PASSWORD); } catch (SQLException e) { System.out.println("Failed to create Connection"); return null; } System.out.println("Connection created Successfully."); return connection; } } |
Output
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 |
Connection created Successfully. Total Number of Columns are :: 5 Column Name ::id Column Type ::4 Column Type Name ::INT ------------------------------- Column Name ::first_name Column Type ::12 Column Type Name ::VARCHAR ------------------------------- Column Name ::last_name Column Type ::12 Column Type Name ::VARCHAR ------------------------------- Column Name ::designation Column Type ::12 Column Type Name ::VARCHAR ------------------------------- Column Name ::salary Column Type ::4 Column Type Name ::INT ------------------------------- |