TGIS_DbAbstract class

Abstract base class for database engines used by SQL-backed GIS layers.

Available also on: .NET | Java.

Syntax

// Delphi
type
  TGIS_DbAbstract = class( TGIS_ObjectDisposable )
  end;

// C++ Builder
class PASCALIMPLEMENTATION TGIS_DbAbstract : public TGIS_ObjectDisposable
{
};

Inheritance

→ TGIS_ObjectDisposable

Constructors

Inherited Overrides Protected

	Name	Visibility	Description
	Create	public	Creates an abstract database engine instance and initializes default SQL dialect and provider state.

Fields

Inherited Protected

Name	Visibility	Description
FDialect	protected	SQL dialect name.
FFullSafeParam	protected	True to return a safe parameter prefix with the parameter name; otherwise only the prefix is returned.
FGeometryType	protected	Internal geometry storage subtype for the current provider.
FiCodePage	protected	Cached code page value used for optimization.
FiJoinCodePage	protected	Cached join code page value used for optimization.
FInBatchMode	protected	True, if batch mode is enabled.
FisDb2	protected	True if the current SQL dialect is IBM DB2.
FisInformix	protected	True if the current SQL dialect is Informix.
FIsInitializedProvider	protected	True if the database provider has been initialized.
FisInterbase	protected	True if the current SQL dialect is InterBase.
FIsJDBC	protected	True if JDBC (Java Database Connectivity) is used.
FisMsJet	protected	True if the current SQL dialect is Microsoft Jet.
FisMsSql	protected	True if the current SQL dialect is Microsoft SQL Server.
FisMySql	protected	True if the current SQL dialect is MySQL.
FisOracle	protected	True if the current SQL dialect is Oracle.
FisPostgreSql	protected	True if the current SQL dialect is PostgreSQL.
FisSqlite	protected	True if the current SQL dialect is SQLite.
FisSybase	protected	True if the current SQL dialect is Sybase.
FMultiUserMode	protected	Multiuser mode for database access and update behavior.
FNameMaxLength	protected	Maximum length allowed for SQL object names.
FOnSQLExecute	protected	Event handler called before an SQL command is executed.
FParameterPrefix	protected	SQL parameter prefix used by the current provider.
FReuseQuery	protected	If True, reuse opened query, otherwise open a new query.
FRowsetSize	protected	Number of rows fetched in batches from the cursor database (default 0).
FUseTextParameters	protected	Use text parameters.
options	protected	Engine options.

Methods

Inherited Overrides Protected

Name	Visibility	Description
cursorClose	public	Free a cursor allocated by cursorOpen().
cursorOpen	public	Allocate a new cursor.
FinalizeProvider	public	Finalizes the database provider backend.
getLastCursor	public	Get last opened cursor index.
GetLastErrorMessage	public	Returns the last database provider error message.
InitializeProvider	public	Initializes the database provider backend.
PreRecognize	public	Checks whether the database provider can recognize and open a layer configuration for the specified path, storage, and SQL type.
safeParam	public	Get a safe parameter.
sqlBaseFolder	public	Return base folder for a layer.
sqlBindField	public	Obtain a bind number for a given field name.
sqlBuild	public	Build a new SQL layer.
sqlConnect	public	Opens a database connection using the provider-specific SQL parameters.
sqlCreateFunction	public	Create a function on the database side.
sqlDisconnect	public	Close database connection.
sqlExec	public	Executes an SQL command that does not return a cursor.
sqlGetBindedField	public	Get the value of a binded field for the current shape from the database.
sqlGetParams	public	Get a parameters list.
sqlInitialize	public	Initializes SQL dialect flags and engine options from connection parameters and dialect definitions.
sqlLastInsertId	public	Get last inserted record id.
sqlPathAbsolute(String; String; Boolean)	public	Resolves potentially embedded database path in a connection string into an absolute path.
sqlPathAbsolute(String; String; Char; Boolean)	public	Resolves potentially embedded database path in a connection string into an absolute path.
sqlPathAbsolute(String; String; Char; String; Char)	public	Resolves a file path embedded in a connection string into an absolute path.
sqlQueryClose	public	Closes the query cursor.
sqlQueryEof	public	Tests whether the query cursor reached EOF and closes the query when EOF is reached.
sqlQueryGeometryIsText	public	Test whether geometry data is stored as text.
sqlQueryGetBlob	public	Get blob data from the query.
sqlQueryGetField	public	Get a field from the query by field name.
sqlQueryGetFieldById	public	Get a field from the query by field index.
sqlQueryGetFieldIndex	public	Get field index from query.
sqlQueryGetGeomObj	public	Get a geometry object from the query.
sqlQueryGetGeomPtr	public	Get geometry data from the query as a pointer.
sqlQueryGetGeomVAR	public	Get geometry data from the query as an OleVariant value.
sqlQueryGetGEOUID(Integer; Integer)	public	Get a GEO.UID value from the query by field index.
sqlQueryGetGEOUID(String; Integer)	public	Get a GEO.UID value from the query by field name.
sqlQueryGetSHAPETYPE	public	Get a SHAPETYPE value from the query.
sqlQueryGetXMIN	public	Get an XMIN value from the query.
sqlQueryGetYMIN	public	Get a YMIN value from the query.
sqlQueryMoveFirst	public	Move to first record of query.
sqlQueryMoveNext	public	Move to next record of query.
sqlQueryNameGEOUID	public	Get the GEO.UID field value from the query.
sqlQueryOpen	public	Opens a query and closes any previously active query for the same cursor.
sqlQueryReset	public	Resets the current SQL query for the specified cursor.
sqlQueryStructure	public	Fill the current layer structure based on the query.
sqlQueryUnPrepareGetGeom	public	Unprepare geometry access.
sqlTableAppend	public	Append a new record into the table.
sqlTableClose	public	Close the table.
sqlTableCreateParam	public	Create a table parameter.
sqlTableEof	public	Tests whether the table cursor reached EOF and closes the table when EOF is reached.
sqlTableExec	public	Execute opened table command.
sqlTableGetField	public	Get a field from the table.
sqlTableGetParam	public	Get a parameter value from the table.
sqlTableOpenRead	public	Opens a table for read access using the provided filter query.
sqlTableOpenWrite	public	Opens a table for write access using the provided filter query.
sqlTablePost	public	Update the table (after any change).
sqlTablePrepared	public	Returns whether the table is prepared for inserting a new record.
sqlTableSetBlob	public	Set blob data in the table.
sqlTableSetField	public	Set a field value in the table.
sqlTableSetGeometry(Integer; String; OleVariant; TGIS_MemoryStream)	public	Set geometry data in the table.
sqlTableSetGeometry(Integer; String; TObject)	public	Set geometry data in the table.
sqlTransactGlobalUpdateCommit	public	Commits the current global transaction.
sqlTransactGlobalUpdateStart	public	Starts a global transaction for grouped updates.
sqlTransactRestructCommit	public	Commits the current restructure transaction.
sqlTransactRestructStart	public	Starts a restructure transaction.
sqlTransactRollback	public	Rollback global transaction.
sqlTransactUpdateCommit	public	Commits the current update transaction.
sqlTransactUpdateStart	public	Starts an update transaction.
sqlUpdateStart	public	Start update operations for the table.

Properties

Inherited Protected

Name	Visibility	Description
CurrentSQLDialect	public	Current SQL dialect name.
EngineOptions	public	Engine option flags controlling database provider behavior.
FullSafeParam	public	True to return the safe parameter prefix together with the parameter name; False to return only the prefix.
GeometryType	public	Internal geometry type.
iCodePage	public	Code page used for string conversion.
iJoinCodePage	public	Code page used for join field string conversion.
InBatchMode	public	True, if batch mode is enabled for fast inserts.
IsDb2	public	True if the current SQL dialect is DB2.
IsInformix	public	True if the current SQL dialect is Informix.
IsInterbase	public	True if the current SQL dialect is InterBase.
IsJDBC	public	True if JDBC (Java Database Connectivity) is used.
IsMsJet	public	True if the current SQL dialect is Microsoft Jet.
IsMsSql	public	True if the current SQL dialect is Microsoft SQL Server.
IsMySql	public	True if the current SQL dialect is MySQL.
IsOracle	public	True if the current SQL dialect is Oracle.
IsPostgreSql	public	True if the current SQL dialect is PostgreSQL.
IsProviderInitialized	public	True if the provider has been initialized.
IsSqlite	public	True if the current SQL dialect is SQLite.
IsSybase	public	True if the current SQL dialect is Sybase.
MultiUserMode	public	Multiuser mode.
NameMaxLength	public	Maximum SQL identifier name length.
ParameterPrefix	public	SQL parameter prefix used when formatting parameterized commands.
RowsetSize	public	Number of rows fetched from the database cursor in each batch operation; 0 uses provider defaults.
UseTextParameters	public	Use text parameters.

Events

Inherited Protected

	Name	Visibility	Description
	SQLExecuteEvent	published	Fired before an SQL statement is executed.

Remarks

Reuse query

By default, if a query sql doesn't change, an existing dataset is reused. To always make a recreation of a query reflecting changes in a table that was modified manually in the database, REUSEQUERY options can be used either by :

adding REUSEQUERY=false to a connector file or embedded Path, or
adding a global metadata key TGIS_DbAbstract.REUSEQUERY with value 'true'

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Table of Contents

TGIS_DbAbstract class

Syntax

Inheritance

Constructors

Fields

Methods

Properties

Events

Remarks

Reuse query

TatukGIS Developer Kernel

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Table of Contents

TGIS_DbAbstract class

Syntax

Inheritance

Constructors

Fields

Methods

Properties

Events

Remarks

Reuse query

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