hive通過jdbc建立表,分割槽,桶
阿新 • • 發佈:2019-01-04
首先我們需要開啟hiveserver服務:hive --service hiveserver
然後我們和操作普通資料庫一樣,先載入驅動,然後建立連線,接著建立一個statement,然後執行查詢,然會結果集。程式碼如下(一定要寫對sql語句,要仔細,下面的需要注意的地方我已經標示出來了:)
package playHive; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; public class HiveJdbcClient { private final static String driverName = "org.apache.hadoop.hive.jdbc.HiveDriver"; private final static String localFilePath="/home/hadoop/test/hive/test.txt"; private final static String hdfsFilePath="hdfs://192.168.0.1:9000/user/hadoop/"; private final static String tableName="testHiveDriverTable"; private final static String partitionName="testHiveDriverPartition"; private final static String bucketName="testHiveDriverBucket"; private static String sql = ""; private static Connection connection ; private static Statement statement; private static ResultSet resultSet; static { try { Class.forName(driverName); } catch (ClassNotFoundException e) { System.out.println(e); System.exit(1); } try { connection = DriverManager.getConnection( "jdbc:hive://192.168.0.1:50000/default", "hive", "hadoop"); //首先要開啟hiveserver服務:hive --service hiveserver statement = connection.createStatement(); } catch (Exception e) { e.printStackTrace(); } } public static void createTable() throws SQLException { sql = "drop table " + tableName; System.out.println("delete table****"); statement.executeQuery(sql); sql = "create table " + tableName + " (key int,value String)" + " row format delimited fields terminated by '\t'"; System.out.println("create table:"+tableName); statement.executeQuery(sql); showTable(); describeTable(); } public static void showTable() throws SQLException { sql = "show tables " + tableName; System.out.println("show table:"+tableName); resultSet=statement.executeQuery(sql); while(resultSet.next()){ System.out.println(resultSet.getString(1)); } } public static void describeTable() throws SQLException{ sql="describe "+tableName; System.out.println("describe table:"+tableName); resultSet=statement.executeQuery(sql); while(resultSet.next()){ System.out.println(resultSet.getString(1)+"\t"+resultSet.getString(2)); } } public static void loadDataToTable(boolean isLocal) throws SQLException{ sql=isLocal?"load data local inpath '"+localFilePath+"' overwrite into table "+tableName: "load data inpath '"+hdfsFilePath+"' overwrite into table "+tableName; System.out.println("load data into table:"+tableName); statement.executeQuery(sql); } public static void queryTable() throws SQLException{ sql="select * from "+tableName; System.out.println("execute query:select *query"); resultSet=statement.executeQuery(sql); while(resultSet.next()){ System.out.println(resultSet.getString(1)+'\t'+resultSet.getString(2)); } } public static void regularTableQuery() throws SQLException{ //sql="select count(1) from "+tableName+";"; sql="select key,max(n) from (select key,count(value) as n from "+tableName+" group by key)sbuq group by key"; System.out.println("execute query:"); resultSet =statement.executeQuery(sql); while(resultSet.next()){ System.out.println(resultSet.getString(1)); } } public static void createPartition() throws SQLException{ sql="drop table "+partitionName; System.out.println("delete partition"); statement.execute(sql); sql="create table "+partitionName+"(key int) partitioned by (value string) " + "row format delimited fields terminated by '\t'"; System.out.println("create partition:"+partitionName); statement.execute(sql); } public static void insertDataToPartition() throws SQLException{ //這裡一定是select key from "+tableName;key不可以寫成value,否則不能插入進去,插入的值將會是null sql="insert overwrite table "+partitionName+" partition (value='qinqin') select key from "+tableName; statement.execute(sql); System.out.println("insert data to "+partitionName+" success"); } public static void selectFromPartition() throws SQLException{ sql="select * from "+partitionName+" where value='qinqin'"; System.out.println("query in partition:select * in "+partitionName); resultSet=statement.executeQuery(sql); while(resultSet.next()){ System.out.println(resultSet.getString(1)); } } public static void createBucket() throws SQLException{ sql="drop table "+bucketName; System.out.println("delete bucket"); statement.executeQuery(sql); sql="create table "+bucketName+"(key int,value string) clustered by(key) into 3 buckets " + "row format delimited fields terminated by '\t'"; System.out.println("create bucket:"+bucketName); statement.execute(sql); } public static void insertDataToBucket() throws SQLException{ sql="insert overwrite table "+bucketName+" select key,value from "+tableName; System.out.println("insert data into bucket:"+bucketName); statement.executeQuery(sql); } public static void selectFromBucket() throws SQLException{ sql="select * from "+bucketName+" tablesample(bucket 1 out of 3 on key)"; System.out.println("select from bucket:"+bucketName); resultSet=statement.executeQuery(sql); while(resultSet.next()){ System.out.println(resultSet.getString(1)+"\t" +resultSet.getString(2)); } } public static void closeConnection(){ try { connection.close(); } catch (SQLException e) { e.printStackTrace(); System.exit(1); } } public static void tableOperation() throws SQLException{ HiveJdbcClient.createTable(); HiveJdbcClient.loadDataToTable(true); HiveJdbcClient.queryTable(); HiveJdbcClient.regularTableQuery(); } public static void partitionOperation() throws SQLException{ HiveJdbcClient.createPartition(); HiveJdbcClient.insertDataToPartition(); HiveJdbcClient.selectFromPartition(); } public static void bucketOperation() throws SQLException{ HiveJdbcClient.createBucket(); HiveJdbcClient.insertDataToBucket(); HiveJdbcClient.selectFromBucket(); } public static void main(String[] args) { try { System.out.println("table Operation***********************************************"); //HiveJdbcClient.tableOperation(); System.out.println("partition Operation***********************************************"); HiveJdbcClient.partitionOperation(); System.out.println("bucket Operation***********************************************"); //HiveJdbcClient.bucketOperation(); HiveJdbcClient.closeConnection(); } catch (SQLException e) { e.printStackTrace(); } } }