[Overview][Constants][Types][Classes][Procedures and functions][Variables][Index] | Reference for unit 'DB' (#fcl)

# Reference for unit 'DB'

Database access layer

`uses`
`System,`
`Classes,`
`sysutils,`
`Variants,`
`FmtBCD,` |  | BCD support
`MaskUtils;` |  | Mask string support

## Overview

The db unit provides the basis for all database access mechanisms. It introduces abstract classes, on which all database access mechanisms are based: TDataset representing a set of records from a database, TField which represents the contents of a field in a record, TDatasource which acts as an event distributor on behalf of a dataset and TParams which can be used to parameterize queries. The databases connections themselves are abstracted in the TDatabase class.