Read Access

Synopsis

This operator reads an ExampleSet from a Microsoft Access database.

Description

The Read Access operator is used for reading an ExampleSet from the specified Microsoft Access database (.mdb or .accdb extension). You need to have at least basic understanding of databases, database connections and queries in order to use this operator properly. Go through the parameters and Example Process to understand the flow of this operator.

Output

output

This port delivers the result of the query on database in tabular form along with the meta data. This output is similar to the output of the Retrieve operator.

Parameters

Username

This parameter is used to specify the username of the database (if any).

Password

This parameter is used to specify the password of the database (if any).

Define query

查询is a statement that is used to select required data from the database. This parameter specifies whether the database query should be defined directly, through a file or implicitly by a given table name. The SQL query can be auto generated giving a table name, passed to RapidMiner via a parameter or, in case of long SQL statements, in a separate file. The desired behavior can be chosen using thedefine queryparameter. Please note that column names are often case sensitive and might need quoting.

查询

This parameter is only available when thedefine queryparameter is set to 'query'. This parameter is used to define the SQL query to select desired data from the specified database.

查询file

This parameter is only available when thedefine queryparameter is set to 'query file'. This parameter is used to select a file that contains the SQL query to select desired data from the specified database. Long queries are usually stored in files. Storing queries in files can also enhance reusability.

Table name

This parameter is only available when thedefine queryparameter is set to 'table name'. This parameter is used to select the required table from the specified database.

Database file

This parameter specifies the path of the Access database i.e. the mdb or accdb file.