org.linqs.psl.database.rdbms.driver

Class H2DatabaseDriver

java.lang.Object

org.linqs.psl.database.rdbms.driver.H2DatabaseDriver

All Implemented Interfaces:

DatabaseDriver

public class H2DatabaseDriver
extends Object
implements DatabaseDriver

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	H2DatabaseDriver.Type

Constructor Summary

Constructors

Constructor and Description
H2DatabaseDriver(H2DatabaseDriver.Type dbType, String path, boolean clearDB) Constructor for the H2 database driver.

Method Summary

Modifier and Type	Method and Description
void	bulkCopy(String path, String delimiter, boolean hasTruth, PredicateInfo predicateInfo, Partition partition) Perform a bulk copy operation to load the file directly into the database.
void	close() Close out any outstanding connections and cleanup.
String	finalizeCreateTable(com.healthmarketscience.sqlbuilder.CreateTableQuery createTable) Gives the driver a chance to perform any final manipulations to the CREATE TABLE statement.
Connection	getConnection() Returns a connection to the database.
String	getDoubleTypeName() Get the type name for a double type.
String	getStringAggregate(String columnName, String delimiter, boolean distinct) Get a string aggregating expression (one that would appear in the SELECT clause of a grouping query.
String	getSurrogateKeyColumnDefinition(String columnName) Get the SQL definition for a primary, surrogate (auto-increment) key for use in a CREATE TABLE statement.
String	getTypeName(ConstantType type) Get the type name for each argument type.
String	getUpsert(String tableName, String[] columns, String[] keyColumns) Get the SQL for an upsert (merge) on the specified table and columns.
boolean	supportsBulkCopy() Returns whether the underline database supports bulk copying operations.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

H2DatabaseDriver

public H2DatabaseDriver(H2DatabaseDriver.Type dbType,
                        String path,
                        boolean clearDB)

Constructor for the H2 database driver.

Parameters:

dbType - Type of database, either Disk or Memory.

path - Path to database on disk, or name if type is Memory.

clearDB - Whether to perform a DROP ALL on the database after connecting.

Method Detail

close

public void close()

Description copied from interface: DatabaseDriver

Close out any outstanding connections and cleanup.

Specified by:

close in interface DatabaseDriver

getConnection

public Connection getConnection()

Description copied from interface: DatabaseDriver

Returns a connection to the database. Database drivers are expected to fully connect at instantiation (i.e. in the constructor). Implementation are expected to use connection pools. The connections retutned from this methods should be safe to close() without significant performance impact.

Specified by:

getConnection in interface DatabaseDriver

Returns:

the connection to the database, as specified in the DatabaseDriver constructor

supportsBulkCopy

public boolean supportsBulkCopy()

Description copied from interface: DatabaseDriver

Returns whether the underline database supports bulk copying operations.

Specified by:

supportsBulkCopy in interface DatabaseDriver

bulkCopy

public void bulkCopy(String path,
                     String delimiter,
                     boolean hasTruth,
                     PredicateInfo predicateInfo,
                     Partition partition)

Description copied from interface: DatabaseDriver

Perform a bulk copy operation to load the file directly into the database. May not be supported by all backends.

Specified by:

bulkCopy in interface DatabaseDriver

getTypeName

public String getTypeName(ConstantType type)

Description copied from interface: DatabaseDriver

Get the type name for each argument type.

Specified by:

getTypeName in interface DatabaseDriver

getSurrogateKeyColumnDefinition

public String getSurrogateKeyColumnDefinition(String columnName)

Description copied from interface: DatabaseDriver

Get the SQL definition for a primary, surrogate (auto-increment) key for use in a CREATE TABLE statement.

Specified by:

getSurrogateKeyColumnDefinition in interface DatabaseDriver

getDoubleTypeName

public String getDoubleTypeName()

Description copied from interface: DatabaseDriver

Get the type name for a double type.

Specified by:

getDoubleTypeName in interface DatabaseDriver

getUpsert

public String getUpsert(String tableName,
                        String[] columns,
                        String[] keyColumns)

Description copied from interface: DatabaseDriver

Get the SQL for an upsert (merge) on the specified table and columns. An "upsert" updates existing records and inserts where there is no record. Most RDBMSs support some for of upsert, but the syntax is inconsistent. The parameters for the statement should the the specified columns in order. Some databases (like H2) require knowing the key columns we need to use.

Specified by:

getUpsert in interface DatabaseDriver

finalizeCreateTable

public String finalizeCreateTable(com.healthmarketscience.sqlbuilder.CreateTableQuery createTable)

Description copied from interface: DatabaseDriver

Gives the driver a chance to perform any final manipulations to the CREATE TABLE statement.

Specified by:

finalizeCreateTable in interface DatabaseDriver

getStringAggregate

public String getStringAggregate(String columnName,
                                 String delimiter,
                                 boolean distinct)

Description copied from interface: DatabaseDriver

Get a string aggregating expression (one that would appear in the SELECT clause of a grouping query. Postgres uses STRING_AGG and H2 use GROUP_CONCAT.

Specified by:

getStringAggregate in interface DatabaseDriver