/// <exception cref="Java.Sql.SQLException"/>
public OracleDBRecordReader(DBInputFormat.DBInputSplit split, Type inputClass, Configuration
conf, Connection conn, DBConfiguration dbConfig, string cond, string[] fields,
string table)
: base(split, inputClass, conf, conn, dbConfig, cond, fields, table)
{
SetSessionTimeZone(conf, conn);
}
/// <exception cref="Java.Sql.SQLException"/>
public OracleDataDrivenDBRecordReader(DBInputFormat.DBInputSplit split, Type inputClass
, Configuration conf, Connection conn, DBConfiguration dbConfig, string cond, string
[] fields, string table)
: base(split, inputClass, conf, conn, dbConfig, cond, fields, table, "ORACLE")
{
// Must initialize the tz used by the connection for Oracle.
OracleDBRecordReader.SetSessionTimeZone(conf, conn);
}
/// <param name="split">The InputSplit to read data for</param>
/// <exception cref="Java.Sql.SQLException"></exception>
public DataDrivenDBRecordReader(DBInputFormat.DBInputSplit split, Type inputClass
, Configuration conf, Connection conn, DBConfiguration dbConfig, string cond, string
[] fields, string table, string dbProduct)
: base(split, inputClass, conf, conn, dbConfig, cond, fields, table)
{
// database manufacturer string.
this.dbProductName = dbProduct;
}
/// <summary>Returns the query for selecting the records from an Oracle DB.</summary>
protected internal override string GetSelectQuery()
{
StringBuilder query = new StringBuilder();
DBConfiguration dbConf = GetDBConf();
string conditions = GetConditions();
string tableName = GetTableName();
string[] fieldNames = GetFieldNames();
// Oracle-specific codepath to use rownum instead of LIMIT/OFFSET.
if (dbConf.GetInputQuery() == null)
{
query.Append("SELECT ");
for (int i = 0; i < fieldNames.Length; i++)
{
query.Append(fieldNames[i]);
if (i != fieldNames.Length - 1)
{
query.Append(", ");
}
}
query.Append(" FROM ").Append(tableName);
if (conditions != null && conditions.Length > 0)
{
query.Append(" WHERE ").Append(conditions);
}
string orderBy = dbConf.GetInputOrderBy();
if (orderBy != null && orderBy.Length > 0)
{
query.Append(" ORDER BY ").Append(orderBy);
}
}
else
{
//PREBUILT QUERY
query.Append(dbConf.GetInputQuery());
}
try
{
DBInputFormat.DBInputSplit split = GetSplit();
if (split.GetLength() > 0)
{
string querystring = query.ToString();
query = new StringBuilder();
query.Append("SELECT * FROM (SELECT a.*,ROWNUM dbif_rno FROM ( ");
query.Append(querystring);
query.Append(" ) a WHERE rownum <= ").Append(split.GetEnd());
query.Append(" ) WHERE dbif_rno > ").Append(split.GetStart());
}
}
catch (IOException)
{
}
// ignore, will not throw.
return(query.ToString());
}
/// <param name="split">The InputSplit to read data for</param>
/// <exception cref="Java.Sql.SQLException"></exception>
public DBRecordReader(DBInputFormat.DBInputSplit split, Type inputClass, Configuration
conf, Connection conn, DBConfiguration dbConfig, string cond, string[] fields,
string table)
{
this.inputClass = inputClass;
this.split = split;
this.conf = conf;
this.connection = conn;
this.dbConf = dbConfig;
this.conditions = cond;
this.fieldNames = fields;
this.tableName = table;
}
/// <summary>test generate sql script for OracleDBRecordReader.</summary>
/// <exception cref="System.Exception"/>
public virtual void TestOracleDBRecordReader()
{
DBInputFormat.DBInputSplit splitter = new DBInputFormat.DBInputSplit(1, 10);
Configuration configuration = new Configuration();
Connection connect = DriverForTest.GetConnection();
DBConfiguration dbConfiguration = new DBConfiguration(configuration);
dbConfiguration.SetInputOrderBy("Order");
string[] fields = new string[] { "f1", "f2" };
OracleDBRecordReader <DBInputFormat.NullDBWritable> recorder = new OracleDBRecordReader
<DBInputFormat.NullDBWritable>(splitter, typeof(DBInputFormat.NullDBWritable), configuration
, connect, dbConfiguration, "condition", fields, "table");
NUnit.Framework.Assert.AreEqual("SELECT * FROM (SELECT a.*,ROWNUM dbif_rno FROM ( SELECT f1, f2 FROM table WHERE condition ORDER BY Order ) a WHERE rownum <= 10 ) WHERE dbif_rno > 1"
, recorder.GetSelectQuery());
}
/// <exception cref="Java.Sql.SQLException"/>
public MySQLDBRecordReader(DBInputFormat.DBInputSplit split, Type inputClass, Configuration
conf, Connection conn, DBConfiguration dbConfig, string cond, string[] fields,
string table)
: base(split, inputClass, conf, conn, dbConfig, cond, fields, table)
{
}
/// <summary>
/// <inheritDoc/>
///
/// </summary>
/// <exception cref="System.IO.IOException"/>
public override IList <InputSplit> GetSplits(JobContext job)
{
ResultSet results = null;
Statement statement = null;
try
{
statement = connection.CreateStatement();
results = statement.ExecuteQuery(GetCountQuery());
results.Next();
long count = results.GetLong(1);
int chunks = job.GetConfiguration().GetInt(MRJobConfig.NumMaps, 1);
long chunkSize = (count / chunks);
results.Close();
statement.Close();
IList <InputSplit> splits = new AList <InputSplit>();
// Split the rows into n-number of chunks and adjust the last chunk
// accordingly
for (int i = 0; i < chunks; i++)
{
DBInputFormat.DBInputSplit split;
if ((i + 1) == chunks)
{
split = new DBInputFormat.DBInputSplit(i * chunkSize, count);
}
else
{
split = new DBInputFormat.DBInputSplit(i * chunkSize, (i * chunkSize) + chunkSize
);
}
splits.AddItem(split);
}
connection.Commit();
return(splits);
}
catch (SQLException e)
{
throw new IOException("Got SQLException", e);
}
finally
{
try
{
if (results != null)
{
results.Close();
}
}
catch (SQLException)
{
}
try
{
if (statement != null)
{
statement.Close();
}
}
catch (SQLException)
{
}
CloseConnection();
}
}
/// <exception cref="System.IO.IOException"/>
protected internal virtual RecordReader <LongWritable, T> CreateDBRecordReader(DBInputFormat.DBInputSplit
split, Configuration conf)
{
Type inputClass = (Type)(dbConf.GetInputClass());
try
{
// use database product name to determine appropriate record reader.
if (dbProductName.StartsWith("ORACLE"))
{
// use Oracle-specific db reader.
return(new OracleDBRecordReader <T>(split, inputClass, conf, CreateConnection(), GetDBConf
(), conditions, fieldNames, tableName));
}
else
{
if (dbProductName.StartsWith("MYSQL"))
{
// use MySQL-specific db reader.
return(new MySQLDBRecordReader <T>(split, inputClass, conf, CreateConnection(), GetDBConf
(), conditions, fieldNames, tableName));
}
else
{
// Generic reader.
return(new DBRecordReader <T>(split, inputClass, conf, CreateConnection(), GetDBConf
(), conditions, fieldNames, tableName));
}
}
}
catch (SQLException ex)
{
throw new IOException(ex.Message);
}
}
/// <exception cref="System.IO.IOException"/>
protected internal override RecordReader <LongWritable, T> CreateDBRecordReader(DBInputFormat.DBInputSplit
split, Configuration conf)
{
DBConfiguration dbConf = GetDBConf();
Type inputClass = (Type)(dbConf.GetInputClass());
try
{
// Use Oracle-specific db reader
return(new OracleDataDrivenDBRecordReader <T>(split, inputClass, conf, CreateConnection
(), dbConf, dbConf.GetInputConditions(), dbConf.GetInputFieldNames(), dbConf.GetInputTableName
()));
}
catch (SQLException ex)
{
throw new IOException(ex.Message);
}
}
/// <exception cref="System.IO.IOException"/>
protected internal override RecordReader <LongWritable, T> CreateDBRecordReader(DBInputFormat.DBInputSplit
split, Configuration conf)
{
DBConfiguration dbConf = GetDBConf();
Type inputClass = (Type)(dbConf.GetInputClass());
string dbProductName = GetDBProductName();
Log.Debug("Creating db record reader for db product: " + dbProductName);
try
{
// use database product name to determine appropriate record reader.
if (dbProductName.StartsWith("MYSQL"))
{
// use MySQL-specific db reader.
return(new MySQLDataDrivenDBRecordReader <T>(split, inputClass, conf, CreateConnection
(), dbConf, dbConf.GetInputConditions(), dbConf.GetInputFieldNames(), dbConf.GetInputTableName
()));
}
else
{
// Generic reader.
return(new DataDrivenDBRecordReader <T>(split, inputClass, conf, CreateConnection(
), dbConf, dbConf.GetInputConditions(), dbConf.GetInputFieldNames(), dbConf.GetInputTableName
(), dbProductName));
}
}
catch (SQLException ex)
{
throw new IOException(ex.Message);
}
}