You can use the installer access functions to access the database and the installation process. These functions should only be used by custom installation actions and authoring tools. Some of the installer access functions require SQL query strings for querying the database. Queries must adhere to the installer SQL syntax.

This topic lists the installer database access functions by category.

General Database Access Functions

Function	Description
MsiDatabaseCommit	Commits changes to a database.
MsiDatabaseGetPrimaryKeys	Returns the names of all the primary key columns.
MsiDatabaseIsTablePersistent	Returns an enumeration describing the state of a table.
MsiDatabaseOpenView	Prepares a database query and creates a view object.
MsiGetActiveDatabase	Returns the active database for the installation.
MsiViewGetColumnInfo	Returns column names or definitions.
MsiOpenDatabase	Opens a database file for data access.
MsiViewClose	Releases the result set for an executed view.
MsiViewExecute	Executes the view query and supplies required parameters.
MsiViewFetch	Fetches the next sequential record from the view.
MsiViewGetError	Returns the error that occurred in the MsiViewModify function.
MsiViewModify	Updates a fetched record.

Database Management Functions

Function	Description
MsiCreateTransformSummaryInfo	Creates summary information for an existing transform.
MsiDatabaseApplyTransform	Applies a transform to a database.
MsiDatabaseExport	Exports a table from an open database to a text archive file.
MsiDatabaseGenerateTransform	Generates a transform file of differences between two databases.
MsiDatabaseImport	Imports an installer text archive table into an open database.
MsiDatabaseMerge	Merges two databases together.
MsiGetDatabaseState	Returns the state of the database.

Record Processing Functions

Function	Description
MsiCreateRecord	Creates new record object with specified number of fields.
MsiFormatRecord	Formats record field data and properties using a format string.
MsiRecordClearData	Sets all fields in a record to null.
MsiRecordDataSize	Returns the length of a record field.
MsiRecordGetFieldCount	Returns the number of fields in a record.
MsiRecordGetInteger	Returns the integer value from a record field.
MsiRecordGetString	Returns the string value of a record field.
MsiRecordIsNull	Reports whether a record field is null.
MsiRecordReadStream	Reads bytes from a record stream field into a buffer.
MsiRecordSetInteger	Sets a record field to an integer field.
MsiRecordSetStream	Sets a record stream field from a file.
MsiRecordSetString	Copies a string into the designated field.

Summary Information Property Functions

Function	Description
MsiGetSummaryInformation	Obtains handle to summary information stream of installer database.
MsiSummaryInfoGetProperty	Gets a single property from the summary information.
MsiSummaryInfoGetPropertyCount	Returns number of properties in the summary information stream.
MsiSummaryInfoPersist	Writes changed summary information back to summary information stream.
MsiSummaryInfoSetProperty	Sets a single summary information property.

Installer State Access Functions

Function	Description
MsiGetLanguage	Returns the numeric language of the current installation.
MsiGetLastErrorRecord	Returns error record last returned for the calling process.
MsiGetMode	Returns one of the Boolean internal installation states.
MsiGetProperty	Gets the value of an installer property.
MsiSetProperty	Sets the value of an installation property.
MsiSetMode	Sets an internal engine Boolean state.

Installer Action Functions

Function	Description
MsiDoAction	Executes built-in action, custom action, or user-interface wizard action.
MsiEvaluateCondition	Evaluates a conditional expression containing property names and values.
MsiProcessMessage	Sends an error record to the installer for processing.
MsiSequence	Executes an action sequence.

Installer Location Functions

Function	Description
MsiGetSourcePath	Returns the full source path for a folder in the Directory table.
MsiGetTargetPath	Returns the full target path for a folder in the Directory table.
MsiSetTargetPath	Sets the full target path for a folder in the Directory table.

Installer Selection Functions

Function	Description
MsiEnumComponentCosts	Enumerates the disk-space per drive required to install a component.
MsiGetComponentState	Obtains the state of a component.
MsiGetFeatureCost	Returns the disk space required by a feature.
MsiGetFeatureState	Gets the state of a feature.
MsiGetFeatureValidStates	Returns a valid installation state.
MsiSetComponentState	Sets a component to the specified state.
MsiSetFeatureAttributes	Modifies the default attributes of a feature at run time.
MsiSetFeatureState	Sets a feature to a specified state.
MsiSetInstallLevel	Sets the installation level of a full product installation.
MsiVerifyDiskSpace	Checks for sufficient disk space.

User Interface Functions

Function	Description
MsiEnableUIPreview	Enables preview mode of the user interface.
MsiPreviewBillboard	Displays a billboard with the host control in the displayed dialog box.
MsiPreviewDialog	Displays a dialog box as modeless and inactive.

All functions support both ANSI and Unicode calls. To use these functions, include MsiQuery.h and link with Msi.lib.

Installation Functions

In addition to the database access functions listed above, you create an installation package for an application by using the installer functions listed in the Installer Function Reference section.

< THANKS ME>