The PolyConnection class serves as the entry point for createing the required objects for executing queries and managing transactional contexts.
createStatement
Creates a Statement object for sending SQL statements to the database.
Signature:
Statement createStatement() throws SQLException
Returns:
| Return Type | Description |
|---|---|
| Statement | An object that represents a precompiled SQL statement. |
Throws:
| Exception | Description |
|---|---|
| SQLException | If a database access error occurs or this method is called on a closed connection. |
prepareStatement
Creates a PreparedStatement object for sending parameterized SQL statements to the database.
Signature:
PreparedStatement prepareStatement(String sql) throws SQLException
Parameters:
| Parameter Name | Type | Description |
|---|---|---|
| sql | String | A SQL statement to be sent to the database. |
Returns:
| Return Type | Description |
|---|---|
| PreparedStatement | An object that represents a precompiled SQL statement. |
Throws:
| Exception | Description |
|---|---|
| SQLException | If a database access error occurs or this method is called on a closed connection. |
prepareCall
Creates a CallableStatement object for calling database stored procedures.
Signature:
CallableStatement prepareCall(String sql) throws SQLException
Parameters:
| Parameter Name | Type | Description |
|---|---|---|
| sql | String | A SQL statement to be sent to the database. |
Returns:
| Return Type | Description |
|---|---|
| CallableStatement | An object that represents a call to a stored procedure. |
Throws:
| Exception | Description |
|---|---|
| SQLException | If a database access error occurs or this method is called on a closed connection. |
nativeSQL
Converts a given SQL statement into the system’s native SQL grammar.
Signature:
String nativeSQL(String sql) throws SQLException
Parameters:
| Parameter Name | Type | Description |
|---|---|---|
| sql | String | A SQL statement with JDBC syntax. |
Returns:
| Return Type | Description |
|---|---|
| String | The native SQL query that the database would execute. |
Throws:
| Exception | Description |
|---|---|
| SQLException | If a database access error occurs or this method is called on a closed connection. |
setAutoCommit
Sets this connection’s auto-commit mode to the given state.
Signature:
void setAutoCommit(boolean autoCommit) throws SQLException
Parameters:
| Parameter Name | Type | Description |
|---|---|---|
| autoCommit | boolean | true to enable auto-commit mode; false to disable it. |
Throws:
| Exception | Description |
|---|---|
| SQLException | If a database access error occurs or this method is called on a closed connection. |
getAutoCommit
Retrieves the current auto-commit mode for this Connection object.
Signature:
boolean getAutoCommit() throws SQLException
Returns:
| Return Type | Description |
|---|---|
| boolean | The current state of this Connection object’s auto-commit mode. |
Throws:
| Exception | Description |
|---|---|
| SQLException | If a database access error occurs or this method is called on a closed connection. |
commit
Makes all changes made since the previous commit/rollback permanent.
Signature:
void commit() throws SQLException
Throws:
| Exception | Description |
|---|---|
| SQLException | If a database access error occurs, this method is called while participating in a distributed transaction, or this method is called on a closed connection. |
rollback
Undoes all changes made in the current transaction.
Signature:
void rollback() throws SQLException
Throws:
| Exception | Description |
|---|---|
| SQLException | If a database access error occurs, this method is called while participating in a distributed transaction, or this method is called on a closed connection. |
close
Closes the database connection.
Signature:
void close() throws SQLException
Throws:
| Exception | Description |
|---|---|
| SQLException | If a database access error occurs or the connection is already closed. |
isClosed
Checks whether the connection is closed.
Signature:
boolean isClosed()
Returns:
| Return Type | Description |
|---|---|
| boolean | true if the connection is closed; false otherwise. |
getMetaData
Retrieves the database metadata.
Signature:
DatabaseMetaData getMetaData() throws SQLException
Returns:
| Return Type | Description |
|---|---|
| DatabaseMetaData | An object that contains metadata about the database to which this Connection object is connected. |
Throws:
| Exception | Description |
|---|---|
| SQLException | If a database access error occurs or the connection is closed. |
setReadOnly
Sets the connection to read-only mode.
Signature:
void setReadOnly(boolean readOnly) throws SQLException
Parameters:
| Parameter Name | Type | Description |
|---|---|---|
| readOnly | boolean | true to set the connection to read-only mode; false to allow updates. |
Throws:
| Exception | Description |
|---|---|
| SQLException | If a database access error occurs or the connection is closed. |
isReadOnly
Checks if the connection is in read-only mode.
Signature:
boolean isReadOnly() throws SQLException
Returns:
| Return Type | Description |
|---|---|
| boolean | true if the connection is read-only; false otherwise. |
Throws:
| Exception | Description |
|---|---|
| SQLException | If a database access error occurs or the connection is closed. |
setCatalog
Selects a specific database catalog.
Signature:
void setCatalog(String catalog) throws SQLException
Parameters:
| Parameter Name | Type | Description |
|---|---|---|
| catalog | String | The name of the catalog to select for this connection. |
Throws:
| Exception | Description |
|---|---|
| SQLException | If a database access error occurs or the connection is closed. |
getCatalog
Retrieves the current catalog name.
Signature:
String getCatalog()
Returns:
| Return Type | Description |
|---|---|
| String | The name of the current catalog or null if no catalog is set. |
setTransactionIsolation
Sets the transaction isolation level.
Signature:
void setTransactionIsolation(int level) throws SQLException
Parameters:
| Parameter Name | Type | Description |
|---|---|---|
| level | int | One of the connection transaction isolation levels. |
Throws:
| Exception | Description |
|---|---|
| SQLException | If a database access error occurs, the connection is closed, or the given parameter is not one of the connection transaction isolation levels. |
getTransactionIsolation
Retrieves the current transaction isolation level.
Signature:
int getTransactionIsolation() throws SQLException
Returns:
| Return Type | Description |
|---|---|
| int | The current transaction isolation level. |
Throws:
| Exception | Description |
|---|---|
| SQLException | If a database access error occurs or the connection is closed. |
getWarnings
Retrieves the first SQLWarning reported by calls on this Connection object.
Signature:
SQLWarning getWarnings() throws SQLException
Returns:
| Return Type | Description |
|---|---|
| SQLWarning | The first SQLWarning object or null if there are no warnings. |
Throws:
| Exception | Description |
|---|---|
| SQLException | If a database access error occurs or the connection is closed. |
