Java中DatabaseMetaData 元數據信息

本文轉載自查看原文 2012-08-17 18:08 5823 DataBase

獲取數據庫的相關信息：

1.獲得數據庫的一些相關信息

2.獲得該用戶下面的所有表

3.獲得該用戶下面的所有視圖

4.獲得數據庫中所有方案名稱

5.獲得表或視圖中的所有列信息

6. 獲得一個表的索引信息

7.獲得一個表的主鍵信息

8.獲得一個表的外鍵信息

[java] view plain copy print ?

package com.zsw.test;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
public class DatabaseMetaDateApplication {
private DatabaseMetaData dbMetaData = null;
private Connection con = null;
public DatabaseMetaDateApplication() {
this.getDatabaseMetaData();
}
private void getDatabaseMetaData() {
try {
if (dbMetaData == null) {
Class.forName("com.mysql.jdbc.Driver");
String url = "jdbc:mysql://localhost:3306/creation_cms";
String user = "root";
String password = "root";
con = DriverManager.getConnection(url, user, password);
dbMetaData = con.getMetaData();
}
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}
}
/**
* 獲得數據庫的一些相關信息
*/
public void getDataBaseInformations() {
try {
System.out.println("數據庫已知的用戶: "+ dbMetaData.getUserName());
System.out.println("數據庫的系統函數的逗號分隔列表: "+ dbMetaData.getSystemFunctions());
System.out.println("數據庫的時間和日期函數的逗號分隔列表: "+ dbMetaData.getTimeDateFunctions());
System.out.println("數據庫的字符串函數的逗號分隔列表: "+ dbMetaData.getStringFunctions());
System.out.println("數據庫供應商用於 'schema' 的首選術語: "+ dbMetaData.getSchemaTerm());
System.out.println("數據庫URL: " + dbMetaData.getURL());
System.out.println("是否允許只讀:" + dbMetaData.isReadOnly());
System.out.println("數據庫的產品名稱:" + dbMetaData.getDatabaseProductName());
System.out.println("數據庫的版本:" + dbMetaData.getDatabaseProductVersion());
System.out.println("驅動程序的名稱:" + dbMetaData.getDriverName());
System.out.println("驅動程序的版本:" + dbMetaData.getDriverVersion());
System.out.println();
System.out.println("數據庫中使用的表類型");
ResultSet rs = dbMetaData.getTableTypes();
while (rs.next()) {
System.out.println(rs.getString(1));
}
rs.close();
System.out.println();
} catch (SQLException e) {
e.printStackTrace();
}
}
/**
* 獲得該用戶下面的所有表
*/
public void getAllTableList(String schemaName) {
try {
// table type. Typical types are "TABLE", "VIEW", "SYSTEM TABLE", "GLOBAL TEMPORARY", "LOCAL TEMPORARY", "ALIAS", "SYNONYM".
String[] types = { "TABLE" };
ResultSet rs = dbMetaData.getTables(null, schemaName, "%", types);
while (rs.next()) {
String tableName = rs.getString("TABLE_NAME"); //表名
String tableType = rs.getString("TABLE_TYPE"); //表類型
String remarks = rs.getString("REMARKS"); //表備注
System.out.println(tableName + "-" + tableType + "-" + remarks);
}
} catch (SQLException e) {
e.printStackTrace();
}
}
/**
* 獲得該用戶下面的所有視圖
*/
public void getAllViewList(String schemaName) {
try{
String[] types = { "VIEW" };
ResultSet rs = dbMetaData.getTables(null, schemaName, "%", types);
while (rs.next()){
String viewName = rs.getString("TABLE_NAME"); //視圖名
String viewType = rs.getString("TABLE_TYPE"); //視圖類型
String remarks = rs.getString("REMARKS"); //視圖備注
System.out.println(viewName + "-" + viewType + "-" + remarks);
}
} catch (SQLException e) {
e.printStackTrace();
}
}
/**
* 獲得數據庫中所有方案名稱
*/
public void getAllSchemas(){
try{
ResultSet rs = dbMetaData.getSchemas();
while (rs.next()){
String tableSchem = rs.getString("TABLE_SCHEM");
System.out.println(tableSchem);
}
} catch (SQLException e){
e.printStackTrace();
}
}
/**
* 獲得表或視圖中的所有列信息
*/
public void getTableColumns(String schemaName, String tableName) {
try{
ResultSet rs = dbMetaData.getColumns(null, schemaName, tableName, "%");
while (rs.next()){
String tableCat = rs.getString("TABLE_CAT");//表目錄（可能為空）
String tableSchemaName = rs.getString("TABLE_SCHEM");//表的架構（可能為空）
String tableName_ = rs.getString("TABLE_NAME");//表名
String columnName = rs.getString("COLUMN_NAME");//列名
int dataType = rs.getInt("DATA_TYPE"); //對應的java.sql.Types類型
String dataTypeName = rs.getString("TYPE_NAME");//java.sql.Types類型名稱
int columnSize = rs.getInt("COLUMN_SIZE");//列大小
int decimalDigits = rs.getInt("DECIMAL_DIGITS");//小數位數
int numPrecRadix = rs.getInt("NUM_PREC_RADIX");//基數（通常是10或2）
int nullAble = rs.getInt("NULLABLE");//是否允許為null
String remarks = rs.getString("REMARKS");//列描述
String columnDef = rs.getString("COLUMN_DEF");//默認值
int sqlDataType = rs.getInt("SQL_DATA_TYPE");//sql數據類型
int sqlDatetimeSub = rs.getInt("SQL_DATETIME_SUB"); //SQL日期時間分?
int charOctetLength = rs.getInt("CHAR_OCTET_LENGTH"); //char類型的列中的最大字節數
int ordinalPosition = rs.getInt("ORDINAL_POSITION"); //表中列的索引（從1開始）
/**
* ISO規則用來確定某一列的為空性。
* 是---如果該參數可以包括空值;
* 無---如果參數不能包含空值
* 空字符串---如果參數為空性是未知的
*/
String isNullAble = rs.getString("IS_NULLABLE");
/**
* 指示此列是否是自動遞增
* 是---如果該列是自動遞增
* 無---如果不是自動遞增列
* 空字串---如果不能確定它是否
* 列是自動遞增的參數是未知
*/
String isAutoincrement = rs.getString("IS_AUTOINCREMENT");
System.out.println(tableCat + "-" + tableSchemaName + "-" + tableName_ + "-" + columnName + "-"
+ dataType + "-" + dataTypeName + "-" + columnSize + "-" + decimalDigits + "-" + numPrecRadix
+ "-" + nullAble + "-" + remarks + "-" + columnDef + "-" + sqlDataType + "-" + sqlDatetimeSub
+ charOctetLength + "-" + ordinalPosition + "-" + isNullAble + "-" + isAutoincrement + "-");
}
} catch (SQLException e){
e.printStackTrace();
}
}
/**
* 獲得一個表的索引信息
*/
public void getIndexInfo(String schemaName, String tableName) {
try{
ResultSet rs = dbMetaData.getIndexInfo(null, schemaName, tableName, true, true);
while (rs.next()){
boolean nonUnique = rs.getBoolean("NON_UNIQUE");//非唯一索引(Can index values be non-unique. false when TYPE is tableIndexStatistic )
String indexQualifier = rs.getString("INDEX_QUALIFIER");//索引目錄（可能為空）
String indexName = rs.getString("INDEX_NAME");//索引的名稱
short type = rs.getShort("TYPE");//索引類型
short ordinalPosition = rs.getShort("ORDINAL_POSITION");//在索引列順序號
String columnName = rs.getString("COLUMN_NAME");//列名
String ascOrDesc = rs.getString("ASC_OR_DESC");//列排序順序:升序還是降序
int cardinality = rs.getInt("CARDINALITY"); //基數
System.out.println(nonUnique + "-" + indexQualifier + "-" + indexName + "-" + type + "-" + ordinalPosition + "-" + columnName + "-" + ascOrDesc + "-" + cardinality);
}
} catch (SQLException e){
e.printStackTrace();
}
}
/**
* 獲得一個表的主鍵信息
*/
public void getAllPrimaryKeys(String schemaName, String tableName) {
try{
ResultSet rs = dbMetaData.getPrimaryKeys(null, schemaName, tableName);
while (rs.next()){
String columnName = rs.getString("COLUMN_NAME");//列名
short keySeq = rs.getShort("KEY_SEQ");//序列號(主鍵內值1表示第一列的主鍵，值2代表主鍵內的第二列)
String pkName = rs.getString("PK_NAME"); //主鍵名稱
System.out.println(columnName + "-" + keySeq + "-" + pkName);
}
}catch (SQLException e){
e.printStackTrace();
}
}
/**
* 獲得一個表的外鍵信息
*/
public void getAllExportedKeys(String schemaName, String tableName) {
try{
ResultSet rs = dbMetaData.getExportedKeys(null, schemaName, tableName);
while (rs.next()){
String pkTableCat = rs.getString("PKTABLE_CAT");//主鍵表的目錄（可能為空）
String pkTableSchem = rs.getString("PKTABLE_SCHEM");//主鍵表的架構（可能為空）
String pkTableName = rs.getString("PKTABLE_NAME");//主鍵表名
String pkColumnName = rs.getString("PKCOLUMN_NAME");//主鍵列名
String fkTableCat = rs.getString("FKTABLE_CAT");//外鍵的表的目錄（可能為空）出口（可能為null）
String fkTableSchem = rs.getString("FKTABLE_SCHEM");//外鍵表的架構（可能為空）出口（可能為空）
String fkTableName = rs.getString("FKTABLE_NAME");//外鍵表名
String fkColumnName = rs.getString("FKCOLUMN_NAME"); //外鍵列名
short keySeq = rs.getShort("KEY_SEQ");//序列號（外鍵內值1表示第一列的外鍵，值2代表在第二列的外鍵）。
/**
* hat happens to foreign key when primary is updated:
* importedNoAction - do not allow update of primary key if it has been imported
* importedKeyCascade - change imported key to agree with primary key update
* importedKeySetNull - change imported key to NULL if its primary key has been updated
* importedKeySetDefault - change imported key to default values if its primary key has been updated
* importedKeyRestrict - same as importedKeyNoAction (for ODBC 2.x compatibility)
*/
short updateRule = rs.getShort("UPDATE_RULE");
/**
* What happens to the foreign key when primary is deleted.
* importedKeyNoAction - do not allow delete of primary key if it has been imported
* importedKeyCascade - delete rows that import a deleted key
* importedKeySetNull - change imported key to NULL if its primary key has been deleted
* importedKeyRestrict - same as importedKeyNoAction (for ODBC 2.x compatibility)
* importedKeySetDefault - change imported key to default if its primary key has been deleted
*/
short delRule = rs.getShort("DELETE_RULE");
String fkName = rs.getString("FK_NAME");//外鍵的名稱（可能為空）
String pkName = rs.getString("PK_NAME");//主鍵的名稱（可能為空）
/**
* can the evaluation of foreign key constraints be deferred until commit
* importedKeyInitiallyDeferred - see SQL92 for definition
* importedKeyInitiallyImmediate - see SQL92 for definition
* importedKeyNotDeferrable - see SQL92 for definition
*/
short deferRability = rs.getShort("DEFERRABILITY");
System.out.println(pkTableCat + "-" + pkTableSchem + "-" + pkTableName + "-" + pkColumnName + "-"
+ fkTableCat + "-" + fkTableSchem + "-" + fkTableName + "-" + fkColumnName + "-" + keySeq + "-"
+ updateRule + "-" + delRule + "-" + fkName + "-" + pkName + "-" + deferRability);
}
} catch (SQLException e){
e.printStackTrace();
}
}
public void colseCon() {
try {
if (con != null) {
con.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
DatabaseMetaDateApplication metaData = new DatabaseMetaDateApplication();
// metaData.getDataBaseInformations();
// metaData.getAllTableList(null);
// metaData.getAllViewList(null);
// metaData.getAllSchemas();
// metaData.getTableColumns(null, "zsc_admin");
// metaData.getIndexInfo(null, "zsc_admin");
// metaData.getAllPrimaryKeys(null, "zsc_admin");
metaData.getAllExportedKeys(null, "zsc_admin");
}
}

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