SQLDB unit

A set of classes for connecting to SQL databases and running SQL commands on them.

The SQLDB unit defines four main classes to handle data in SQL based databases.

TSQLConnection represents the connection to the database. Here, properties pertaining to the connection (machine, database, user password) must be set. This is an abstract class, which should not be used directly. Per database type (mysql, firebird, postgres, oracle, sqlite) a descendent should be made and used.
TSQLQuery is a TDataset descendent which can be used to view and manipulate the result of an SQL select query. It can also be used to execute all kinds of SQL statements.
TSQLTransaction represents the transaction in which an SQL command is running. SQLDB supports multiple simultaneous transactions in a database connection. For databases that do not support this functionality natively, it is simulated by maintaining multiple connections to the database.
TSQLScript can be used when many SQL commands must be executed on a database, for example when creating a database.

There is also a unified way to retrieve schema information, and a registration for connector types. More information on how to use these components can be found in UsingSQLDB.

Classes and records

`ESQLDatabaseError`	class	SQL database error class.
`TConnectionDef`	class	Connection type definition class.
`TCustomSQLQuery`	class	Custom Class to handle SQL commands (with or without result set).
`TCustomSQLStatement`	class	Object to execute SQL statements without result set.
`TServerIndexDefs`	class	SQLDB specific descendant of the TIndexDefs.
`TSQLConnection`	class	An abstract class representing a connection to a SQL Database.
`TSQLConnector`	class	Universal connection component.
`TSQLCursor`	class	Internal object representing a database result set.
`TSQLDBFieldDef`	class	TFieldDef descendant with room to store engine-specific data.
`TSQLDBFieldDefs`	class	TFieldDefs descendant with room to store engine-specific data.
`TSQLDBParam`	class	TParam descendent used in SQLDB.
`TSQLDBParams`	class	TParams descendant with room to store engine-specific data.
`TSQLHandle`	class	Internal object representing a database internal handle.
`TSQLQuery`	class	Class to handle SQL commands (with or without result set).
`TSQLScript`	class	Component to execute various SQL statements.
`TSQLSequence`	class	Support for applying sequences to fields.
`TSQLStatement`	class	Class to execute non-select SQL statements.
`TSQLStatementInfo`	record	Record to describe a SQL statement.
`TSQLTransaction`	class	Transaction in which a TSQLQuery is handled.

Procedures and functions

`GetConnectionDef`	function	Search for a connection definition by name.
`GetConnectionList`	procedure	Return a list of connection definition names.
`RegisterConnection`	procedure	Register a new connection type for use in the universal connector.
`UnRegisterConnection`	procedure	Unregister a registered connection type.

Types

`TCommitRollbackAction`	enumeration	Transaction actions (unused).
`TConnectionDefClass`	type	Class of TConnectionDef.
`TConnInfoType`	enumeration	Connection information to be retrieved.
`TConnOption`	enumeration	Connection options.
`TConnOptions`	set	Set of TConnOption.
`TDBEventType`	type	Type of database event.
`TDBEventTypes`	type	Set of database event types.
`TDBLogNotifyEvent`	procedure type	Event handler prototype for handling events.
`TLibraryLoadFunction`	procedure type	Library loading function prototype.
`TLibraryUnLoadFunction`	procedure type	Library unloading function prototype.
`TQuoteChars`	type	Type to describe quote characters.
`TRowsCount`	type	A type to contain a result row count.
`TSchemaType`	type	Schema type to retrieve.
`TSQLConnectionClass`	type	Class of TSQLConnection type.
`TSQLConnectionOption`	enumeration	Connection handling options.
`TSQLConnectionOptions`	set	Set of TSQLConnectionOption.
`TSQLQueryOption`	enumeration	SQL Query options.
`TSQLQueryOptions`	set	Set of TSQLQueryOption.
`TSQLSequenceApplyEvent`	enumeration	When to fetch a new sequence number.
`TSQLTransactionOption`	enumeration	Transaction control options.
`TSQLTransactionOptions`	set	Set of TSQLTransactionOption.
`TStatementType`	type	Type describing the kind of SQL statement.

Constants

`DefaultMacroChar`	constant	Default character to use as a macro delimiter.
`DefaultSQLFormatSettings`	constant	Default settings to be used in SQL.
`detActualSQL`	constant	Alias for sqltypes.detActualSQL.
`detCommit`	constant	Alias for sqltypes.detCommit.
`detCustom`	constant	Alias for sqltypes.detCustom.
`detExecute`	constant	Alias for sqltypes.detExecute.
`detFetch`	constant	Alias for sqltypes.detFetch.
`detParamValue`	constant	Alias for sqltypes.detParamValue.
`detPrepare`	constant	Alias for sqltypes.detPrepare.
`detRollBack`	constant	Alias for sqltypes.detRollBack.
`DoubleQuotes`	constant	Double quote delimiters.
`LogAllEvents`	constant	Constant that can be used to select all events.
`LogAllEventsExtra`	constant	All possible event types that must be reported.
`SingleQuotes`	constant	Single quote delimiters.
`StatementTokens`	constant	Array of tokens used to determine the statement type.
`stColumns`	constant	Alias for sqltypes.stColumns.
`stCommit`	constant	Alias for sqltypes.stCommit.
`stDDL`	constant	Alias for sqltypes.stDDL.
`stDelete`	constant	Alias for sqltypes.stDelete.
`stExecProcedure`	constant	Alias for sqltypes.stExecProcedure.
`stGetSegment`	constant	Alias for sqltypes.stGetSegment.
`stIndexes`	constant	Alias for sqltypes.stIndexes.
`stInsert`	constant	Alias for sqltypes.stInsert.
`stNoSchema`	constant	Alias for sqltypes.stUnknown.
`stPackages`	constant	Alias for sqltypes.stPackages.
`stProcedureParams`	constant	Alias for sqltypes.stProcedureParams.
`stProcedures`	constant	Alias for sqltypes.stProcedures.
`stPutSegment`	constant	Alias for sqltypes.stPutSegment.
`stRollback`	constant	Alias for sqltypes.stRollback.
`stSchemata`	constant	Alias for sqlTypes.stSchemata.
`stSelect`	constant	Alias for sqltypes.stSelect.
`stSelectForUpd`	constant	Alias for sqltypes.stSelectForUpd.
`stSequences`	constant	Alias for sqltypes.stSequences.
`stStartTrans`	constant	Alias for sqltypes.stStartTrans.
`stSysTables`	constant	Alias for sqltypes.stSysTables.
`stTables`	constant	Alias for sqltypes.stTables.
`stUnknown`	constant	Alias for sqltypes.stUnknown.
`stUpdate`	constant	Alias for sqltypes.stUpdate.
`TSchemaObjectNames`	constant	Names of the various types of objects.

Variables

GlobalDBLogHook variable Global logging hook.

Topics

`RetrievingSchemaInformation`	topic	Retrieving Schema Information.
`UniversalConnectors`	topic	Using the universal TSQLConnector type.
`UpdateSQLs`	topic	Automatic generation of update SQL statements.
`UsingParams`	topic	Using parameters.
`UsingSQLDB`	topic	Using SQLDB to access databases.

Uses

An experiment, built from development snapshots. Not the official Free Pascal or Lazarus documentation.