Java/Database SQL JDBC/ResultSetMetaData
Содержание
Create Custom RowSet MetaData
<source lang="java">
import java.sql.Connection; import java.sql.DriverManager; import java.sql.Statement; import java.sql.Types; import javax.sql.RowSetMetaData; import javax.sql.rowset.CachedRowSet; import javax.sql.rowset.RowSetMetaDataImpl; import com.sun.rowset.CachedRowSetImpl; public class Main {
public static void main(String[] args) throws Exception {
Connection conn = getHSQLConnection();
System.out.println("Got Connection.");
Statement st = conn.createStatement();
st.executeUpdate("create table survey (id int,name varchar);");
st.executeUpdate("create view surveyView as (select * from survey);");
st.executeUpdate("insert into survey (id,name ) values (1,"nameValue")");
st.executeUpdate("insert into survey (id,name ) values (2,"anotherValue")");
CachedRowSet crs = null;
RowSetMetaData rsMD = new RowSetMetaDataImpl();
rsMD.setColumnCount(2);
rsMD.setColumnName(1, "id");
rsMD.setColumnType(1, Types.VARCHAR);
rsMD.setColumnName(2, "name");
rsMD.setColumnType(2, Types.VARCHAR);
// sets the designated column"s table name, if any, to the given String.
rsMD.setTableName(1, "survey");
rsMD.setTableName(2, "survey");
// use a custom made RowSetMetaData object for CachedRowSet object
crs = new CachedRowSetImpl();
crs.setMetaData(rsMD);
crs.moveToInsertRow();
crs.updateString(1, "1111");
crs.updateString(2, "alex");
crs.insertRow();
crs.moveToInsertRow();
crs.updateString(1, "2222");
crs.updateString(2, "jane");
crs.insertRow();
// if you want to commit changes from a CachedRowSet
// object to your desired datasource, then you must
// create a Connection object.
//
//conn = getHSQLConnection();
// moves the cursor to the remembered cursor position, usually
// the current row. This method has no effect if the cursor is
// not on the insert row.
crs.moveToCurrentRow();
// when the method acceptChanges() is executed, the CachedRowSet
// object"s writer, a RowSetWriterImpl object, is called behind the
// scenes to write the changes made to the rowset to the underlying
// data source. The writer is implemented to make a connection to
// the data source and write updates to it.
crs.acceptChanges(conn);
conn.close();
}
private static Connection getHSQLConnection() throws Exception {
Class.forName("org.hsqldb.jdbcDriver");
System.out.println("Driver Loaded.");
String url = "jdbc:hsqldb:data/tutorial";
return DriverManager.getConnection(url, "sa", "");
}
public static Connection getMySqlConnection() throws Exception {
String driver = "org.gjt.mm.mysql.Driver";
String url = "jdbc:mysql://localhost/demo2s";
String username = "oost";
String password = "oost";
Class.forName(driver);
Connection conn = DriverManager.getConnection(url, username, password);
return conn;
}
public static Connection getOracleConnection() throws Exception {
String driver = "oracle.jdbc.driver.OracleDriver";
String url = "jdbc:oracle:thin:@localhost:1521:caspian";
String username = "mp";
String password = "mp2";
Class.forName(driver); // load Oracle driver
Connection conn = DriverManager.getConnection(url, username, password);
return conn;
}
}
</source>
Get ResultSet Metadata
<source lang="java">
import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.ResultSetMetaData; import java.sql.Statement; public class Main {
public static void main(String[] args) throws Exception {
Connection conn = getMySqlConnection();
System.out.println("Got Connection.");
Statement st = conn.createStatement();
st.executeUpdate("drop table survey;");
st.executeUpdate("create table survey (id int,name varchar(30));");
st.executeUpdate("insert into survey (id,name ) values (1,"nameValue")");
st = conn.createStatement();
ResultSet rs = st.executeQuery("SELECT * FROM survey");
ResultSetMetaData rsMetaData = rs.getMetaData();
int numberOfColumns = rsMetaData.getColumnCount();
System.out.println("resultSet MetaData column Count=" + numberOfColumns);
for (int i = 1; i <= numberOfColumns; i++) {
System.out.println("column MetaData ");
System.out.println("column number " + i);
// indicates the designated column"s normal maximum width in
// characters
System.out.println(rsMetaData.getColumnDisplaySize(i));
// gets the designated column"s suggested title
// for use in printouts and displays.
System.out.println(rsMetaData.getColumnLabel(i));
// get the designated column"s name.
System.out.println(rsMetaData.getColumnName(i));
// get the designated column"s SQL type.
System.out.println(rsMetaData.getColumnType(i));
// get the designated column"s SQL type name.
System.out.println(rsMetaData.getColumnTypeName(i));
// get the designated column"s class name.
System.out.println(rsMetaData.getColumnClassName(i));
// get the designated column"s table name.
System.out.println(rsMetaData.getTableName(i));
// get the designated column"s number of decimal digits.
System.out.println(rsMetaData.getPrecision(i));
// gets the designated column"s number of
// digits to right of the decimal point.
System.out.println(rsMetaData.getScale(i));
// indicates whether the designated column is
// automatically numbered, thus read-only.
System.out.println(rsMetaData.isAutoIncrement(i));
// indicates whether the designated column is a cash value.
System.out.println(rsMetaData.isCurrency(i));
// indicates whether a write on the designated
// column will succeed.
System.out.println(rsMetaData.isWritable(i));
// indicates whether a write on the designated
// column will definitely succeed.
System.out.println(rsMetaData.isDefinitelyWritable(i));
// indicates the nullability of values
// in the designated column.
System.out.println(rsMetaData.isNullable(i));
// Indicates whether the designated column
// is definitely not writable.
System.out.println(rsMetaData.isReadOnly(i));
// Indicates whether a column"s case matters
// in the designated column.
System.out.println(rsMetaData.isCaseSensitive(i));
// Indicates whether a column"s case matters
// in the designated column.
System.out.println(rsMetaData.isSearchable(i));
// indicates whether values in the designated
// column are signed numbers.
System.out.println(rsMetaData.isSigned(i));
// Gets the designated column"s table"s catalog name.
System.out.println(rsMetaData.getCatalogName(i));
// Gets the designated column"s table"s schema name.
System.out.println(rsMetaData.getSchemaName(i));
}
st.close();
conn.close();
}
private static Connection getHSQLConnection() throws Exception {
Class.forName("org.hsqldb.jdbcDriver");
System.out.println("Driver Loaded.");
String url = "jdbc:hsqldb:data/tutorial";
return DriverManager.getConnection(url, "sa", "");
}
public static Connection getMySqlConnection() throws Exception {
String driver = "org.gjt.mm.mysql.Driver";
String url = "jdbc:mysql://localhost/demo2s";
String username = "oost";
String password = "oost";
Class.forName(driver);
Connection conn = DriverManager.getConnection(url, username, password);
return conn;
}
public static Connection getOracleConnection() throws Exception {
String driver = "oracle.jdbc.driver.OracleDriver";
String url = "jdbc:oracle:thin:@localhost:1521:caspian";
String username = "mp";
String password = "mp2";
Class.forName(driver); // load Oracle driver
Connection conn = DriverManager.getConnection(url, username, password);
return conn;
}
}
</source>
Get Table Name From ResultSet Metadata
<source lang="java">
import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.ResultSetMetaData; import java.sql.Statement; public class Main {
public static void main(String[] args) throws Exception {
Connection conn = getMySqlConnection();
System.out.println("Got Connection.");
Statement st = conn.createStatement();
st.executeUpdate("drop table survey;");
st.executeUpdate("create table survey (id int,name varchar(30));");
st.executeUpdate("insert into survey (id,name ) values (1,"nameValue")");
st = conn.createStatement();
ResultSet rs = st.executeQuery("SELECT * FROM survey");
ResultSetMetaData rsMetaData = rs.getMetaData();
int numberOfColumns = rsMetaData.getColumnCount();
System.out.println("resultSet MetaData column Count=" + numberOfColumns);
for (int i = 1; i <= numberOfColumns; i++) {
System.out.println("column MetaData ");
System.out.println("column number " + i);
// get the designated column"s table name.
System.out.println(rsMetaData.getTableName(i));
}
st.close();
conn.close();
}
private static Connection getHSQLConnection() throws Exception {
Class.forName("org.hsqldb.jdbcDriver");
System.out.println("Driver Loaded.");
String url = "jdbc:hsqldb:data/tutorial";
return DriverManager.getConnection(url, "sa", "");
}
public static Connection getMySqlConnection() throws Exception {
String driver = "org.gjt.mm.mysql.Driver";
String url = "jdbc:mysql://localhost/demo2s";
String username = "oost";
String password = "oost";
Class.forName(driver);
Connection conn = DriverManager.getConnection(url, username, password);
return conn;
}
public static Connection getOracleConnection() throws Exception {
String driver = "oracle.jdbc.driver.OracleDriver";
String url = "jdbc:oracle:thin:@localhost:1521:caspian";
String username = "mp";
String password = "mp2";
Class.forName(driver); // load Oracle driver
Connection conn = DriverManager.getConnection(url, username, password);
return conn;
}
}
</source>
Get Table Schema Name From ResultSet Metadata
<source lang="java">
import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.ResultSetMetaData; import java.sql.Statement; public class Main {
public static void main(String[] args) throws Exception {
Connection conn = getMySqlConnection();
System.out.println("Got Connection.");
Statement st = conn.createStatement();
st.executeUpdate("drop table survey;");
st.executeUpdate("create table survey (id int,name varchar(30));");
st.executeUpdate("insert into survey (id,name ) values (1,"nameValue")");
st = conn.createStatement();
ResultSet rs = st.executeQuery("SELECT * FROM survey");
ResultSetMetaData rsMetaData = rs.getMetaData();
int numberOfColumns = rsMetaData.getColumnCount();
System.out.println("resultSet MetaData column Count=" + numberOfColumns);
for (int i = 1; i <= numberOfColumns; i++) {
System.out.println("column MetaData ");
System.out.println("column number " + i);
// Gets the designated column"s table"s schema name.
System.out.println(rsMetaData.getSchemaName(i));
}
st.close();
conn.close();
}
private static Connection getHSQLConnection() throws Exception {
Class.forName("org.hsqldb.jdbcDriver");
System.out.println("Driver Loaded.");
String url = "jdbc:hsqldb:data/tutorial";
return DriverManager.getConnection(url, "sa", "");
}
public static Connection getMySqlConnection() throws Exception {
String driver = "org.gjt.mm.mysql.Driver";
String url = "jdbc:mysql://localhost/demo2s";
String username = "oost";
String password = "oost";
Class.forName(driver);
Connection conn = DriverManager.getConnection(url, username, password);
return conn;
}
public static Connection getOracleConnection() throws Exception {
String driver = "oracle.jdbc.driver.OracleDriver";
String url = "jdbc:oracle:thin:@localhost:1521:caspian";
String username = "mp";
String password = "mp2";
Class.forName(driver); // load Oracle driver
Connection conn = DriverManager.getConnection(url, username, password);
return conn;
}
}
</source>
Getting the Column Names in a Result Set
<source lang="java">
import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.ResultSetMetaData; import java.sql.Statement; public class Main {
public static void main(String[] argv) throws Exception {
String driverName = "com.jnetdirect.jsql.JSQLDriver";
Class.forName(driverName);
String serverName = "127.0.0.1";
String portNumber = "1433";
String mydatabase = serverName + ":" + portNumber;
String url = "jdbc:JSQLConnect://" + mydatabase;
String username = "username";
String password = "password";
Connection connection = DriverManager.getConnection(url, username, password);
Statement stmt = connection.createStatement();
ResultSet rs = stmt.executeQuery("SELECT * FROM mysql_all_table");
ResultSetMetaData rsmd = rs.getMetaData();
int numColumns = rsmd.getColumnCount();
for (int i = 1; i < numColumns + 1; i++) {
String columnName = rsmd.getColumnName(i);
String tableName = rsmd.getTableName(i);
}
}
}
</source>
ResultSet Metadata from Oracle Driver
<source lang="java">
import java.math.BigDecimal; 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 RSMetaData {
public static void main(String[] args) throws Exception {
String driver = "oracle.jdbc.driver.OracleDriver";
Class.forName(driver).newInstance();
String jdbcUrl = "jdbc:oracle:thin:@localhost:1521:ORCL";
Connection conn = DriverManager.getConnection(jdbcUrl, "yourName", "mypwd");
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery("SELECT * FROM Employees");
printColumnInfo(rs);
printColumnNames(rs);
processRs(rs);
rs = stmt.executeQuery("SELECT * FROM Location");
printColumnInfo(rs);
printColumnNames(rs);
processRs(rs);
conn.close();
}
public static void processRs(ResultSet rs) throws SQLException {
ResultSetMetaData rmd = rs.getMetaData();
while (rs.next()) {
for (int col = 1; col <= rmd.getColumnCount(); col++)
getData(rs, rmd.getColumnType(col), col);
}
}
public static void printColumnNames(ResultSet rs) throws SQLException {
ResultSetMetaData rmd = rs.getMetaData();
for (int col = 1; col <= rmd.getColumnCount(); col++)
System.out.println(rmd.getColumnName(col) + " ");
}
public static void getData(ResultSet rs, int type, int colIdx) throws SQLException {
switch (type) {
case java.sql.Types.CHAR:
case java.sql.Types.VARCHAR:
System.out.println(rs.getString(colIdx));
break;
case java.sql.Types.INTEGER:
int i = rs.getInt(colIdx);
System.out.println(i);
break;
case java.sql.Types.NUMERIC:
BigDecimal bd = rs.getBigDecimal(colIdx);
System.out.println(bd.toString());
break;
case java.sql.Types.TIMESTAMP:
case java.sql.Types.DATE:
java.sql.Date d = rs.getDate(colIdx);
System.out.println(d.toString());
break;
}
}
public static void printColumnInfo(ResultSet rs) throws SQLException {
ResultSetMetaData rsmd = rs.getMetaData();
int cols = rsmd.getColumnCount();
for (int colIdx = 1; colIdx <= cols; colIdx++) {
String name = rsmd.getColumnName(colIdx);
int type = rsmd.getColumnType(colIdx);
String typeName = rsmd.getColumnTypeName(colIdx);
System.out.println(name + ", " + type + ", " + typeName);
}
}
}
</source>
