java.lang.Object
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+--stec.sql.Connection
public class Connection extends Object
A session to a specific database used to execute SQL statements.
Fields
Methods
Method
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Description
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clearWarnings
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Clears all warnings.
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close
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Returns this connection to the connection pool.
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commit
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Makes all changes made since the last commit/rollback permanent and
releases any locks held.
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createStatement
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Returns a new SQL Statement object.
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getAutoCommit
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Gets the current state of auto-commit.
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getCatalog
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Returns current catalog name.
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getMetaData
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Returns the database meta data.
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getTransactionIsolation
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Returns the current transaction isolation level.
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getWarnings
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Returns the first warning.
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isClosed
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Returns whether this connection was returned to the connection pool.
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isReadOnly
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Returns whether in read-only mode.
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nativeSQL
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Returns the native form of the given SQL statement.
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prepareCall
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Creates a CallableStatement object from the given SQL statement for calling
database stored procedures.
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prepareStatement
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Creates a PreparedStatement object from the given parameterized SQL statement.
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rollback
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Rolls back all changes made since the last commit/rollback and releases any
locks held.
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setAutoCommit
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Sets the auto-commit mode.
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setCatalog
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Sets the catalog name.
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setReadOnly
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Sets the read-only mode.
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setTransactionIsolation
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Sets the transaction isolation level.
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Notes
Unless auto-commit mode has been disabled, a connection automatically commits
changes after each statement. If auto-commit mode has been disabled, a commit
must be done or changes to the database will not be made.
TRANSACTION_NONE
Transactions are not supported.
Syntax
public static final int TRANSACTION_NONE
Example
int level = Connection.TRANSACTION_NONE;
TRANSACTION_READ_COMMITTED
Prevent dirty reads. Allow non-repeatable reads and phantom reads.
Syntax
public static final int TRANSACTION_READ_COMMITTED
Example
int level = Connection.TRANSACTION_READ_COMMITTED;
TRANSACTION_READ_UNCOMMITTED
Allow dirty reads, non-repeatable reads and phantom reads.
Syntax
public static final int TRANSACTION_READ_UNCOMMITTED
Example
int level = Connection.TRANSACTION_READ_UNCOMMITTED;
TRANSACTION_REPEATABLE_READ
Prevent dirty reads and non-repeatable reads. Allow phantom reads.
Syntax
public static final int TRANSACTION_REPEATABLE_READ
Example
int level = Connection.TRANSACTION_REPEATABLE_READ;
TRANSACTION_SERIALIZABLE
Prevent dirty reads, non-repeatable reads and phantom reads.
Syntax
public static final int TRANSACTION_SERIALIZABLE
Example
int level = Connection.TRANSACTION_SERIALIZABLE;
clearWarnings
Clears all warnings.
Syntax
public void clearWarnings() throws SQLException
Parameters
Returns
Throws
SQLException
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if a database access error occurs.
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Example
con.clearWarnings();
close
Returns this connection to the connection pool.
Syntax
public void clearWarnings() throws SQLException
Parameters
Returns
Throws
SQLException
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if a database access error occurs.
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Example
con.close();
commit
Makes all changes made since the last commit/rollback permanent and
releases any locks held.
Syntax
public void commit() throws SQLException
Parameters
Returns
Throws
SQLException
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if a database access error occurs.
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Example
con.commit();
createStatement
Returns a new SQL Statement object.
Syntax
public Statement createStatement() throws SQLException
Parameters
Returns
Statement
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a new SQL Statement object.
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Throws
SQLException
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if a database access error occurs.
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Example
Statement stmt = con.createStatement();
getAutoCommit
Gets the current state of auto-commit.
Syntax
public boolean getAutoCommit() throws SQLException
Parameters
Returns
boolean
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true if in auto-commit mode, false if not.
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Throws
SQLException
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if a database access error occurs.
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Example
if(!con.getAutoCommit()) con.commit()
getCatalog
Returns current catalog name.
Syntax
public String getCatalog() throws SQLException
Parameters
Returns
String
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the current catalog name, null if none.
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Throws
SQLException
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if a database access error occurs.
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Example
catalog = con.getCatalog()
getMetaData
Returns the database meta data.
Syntax
public DatabaseMetaData getMetaData() throws SQLException
Parameters
Returns
DatabaseMetaData
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a DatabaseMetaData object.
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Throws
SQLException
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if a database access error occurs.
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Example
DatabaseMetaData metadata = con.getMetaData()
getTransactionIsolation
Returns the current transaction isolation level.
Syntax
public int getTransactionIsolation() throws SQLException
Parameters
Returns
int
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the current transaction isolation level.
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Throws
SQLException
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if a database access error occurs.
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Example
int level = con.getTransactionIsolation()
getWarnings
Returns the first SQL warning.
Syntax
public SQLWarning getWarnings() throws SQLException
Parameters
Returns
SQLWarning
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the first SQLWarning, null if none.
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Throws
SQLException
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if a database access error occurs.
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Example
SQLWarning warning = con.getWarnings()
isClosed
Returns whether this connection was returned to the connection pool.
Syntax
public boolean isClosed() throws SQLException
Parameters
Returns
boolean
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true if the connection was returned to the connection pool, false if not.
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Throws
SQLException
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if a database access error occurs.
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Example
if(!con.isClosed()) con.close()
isReadOnly
Returns whether in read-only mode.
Syntax
public boolean isReadOnly() throws SQLException
Parameters
Returns
boolean
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true if in read-only mode, false if not.
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Throws
SQLException
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if a database access error occurs.
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Example
if(!con.isReadOnly()) update(con, record);
nativeSQL
Returns the native form of the given SQL statement.
Syntax
public String nativeSQL(String sql) throws SQLException
Parameters
sql
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the SQL statement to convert.
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Returns
String
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the native form the the specified SQL statement.
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Throws
SQLException
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if a database access error occurs.
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Example
String native = con.nativeSQL(sql);
prepareCall
Creates a CallableStatement object from the given SQL statement for calling
database stored procedures.
Syntax
public CallableStatement prepareCall(String sql) throws SQLException
Parameters
Returns
CallableStatement
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a new CallableStatement object.
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Throws
SQLException
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if a database access error occurs.
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Example
CallableStatement stmt = con.prepareCall(sql);
prepareStatement
Creates a PreparedStatement object from the given parameterized SQL statement.
Syntax
public PreparedStatement prepareStatement(String sql) throws SQLException
Parameters
Returns
PreparedStatement
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a new PreparedStatement object.
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Throws
SQLException
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if a database access error occurs.
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Example
PreparedStatement stmt = con.prepareStatement(sql);
rollback
Rolls back all changes made since the last commit/rollback and releases any
locks held.
Syntax
public void rollback() throws SQLException
Parameters
Returns
Throws
SQLException
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if a database access error occurs.
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Example
con.rollback();
setAutoCommit
Sets the auto-commit mode.
Syntax
public void setAutoCommit(boolean autoCommit) throws SQLException
Parameters
autoCommit
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true to enable auto-commit mode, false to disable auto-commit mode.
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Returns
Throws
SQLException
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if a database access error occurs.
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Example
con.setAutoCommit(true);
setCatalog
Sets the catalog name.
Syntax
public void setCatalog(String catalog) throws SQLException
Parameters
catalog
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the catalog's name.
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Returns
Throws
SQLException
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if a database access error occurs.
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Example
con.setCatalog(catalog);
setReadOnly
Sets the read-only mode.
Syntax
public void setReadOnly(boolean readOnly) throws SQLException
Parameters
readOnly
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true to enable read-only mode, false to disable read-only mode.
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Returns
Throws
SQLException
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if a database access error occurs.
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Example
con.setReadOnly(true);
setTransactionIsolation
Sets the transaction isolation level.
Syntax
public void setTransactionIsolation(int level) throws SQLException
Parameters
level
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the transaction isolation level.
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Returns
Throws
SQLException
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if a database access error occurs.
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Example
con.setTransactionIsolation(level);
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