Reader Directives

The suffixes listed are prefixed by the current <ReaderKeyword> in a mapping file. By default, the <ReaderKeyword> for the Informix reader is INFX.

DATASET

Required/Optional: Required

This is the data source name. On Windows, it is an ODBC data source name.

Example:

INFX_DATASET sample

Workbench Parameter: Source IBM Informix Dataset

USER_NAME

Required/Optional: Optional

The name of the user who will access the database. By default, USER_NAME will be considered the same as the schema name. For example, any table name which explicitly does not have the schema name prefixed will be considered as a table from the schema for that user.

Example:

INFX_USER_NAME bond007

Workbench Parameter: User ID

PASSWORD

Required/Optional: Optional

The password to access the database.

Example:

INFX_PASSWORD moneypenny

Workbench Parameter: Password

DEF

Required/Optional

Optional

Each database table must be defined before it can be read. There are two forms that the definition may take.

The syntax of the first form is:

INFX_DEF <tableName> \
    [SQL_WHERE_CLAUSE  <whereClause>] \
    [<fieldName>  <fieldType>] +

In this form, the fields and their types are listed. The <fieldType> of each field must be given, but it is not verified against the database definition for the field. In effect, it is ignored.

The <tableName> must match a table in the database. This will be used as the feature type of all the features read from the table.

If no <whereClause> is specified, all rows in the table will be read and returned as individual features, unless limited by a global directive:

<ReaderKeyword>_WHERE_CLAUSE

If a <whereClause> is specified, only those rows that are selected by the clause will be read. Note that the <whereClause> does not include the word “WHERE.”

In this example, the all records whose ID is less than 5 will be read from the supplier table:

INFX_DEF supplier \
    INFX_WHERE_CLAUSE "id < 5"	\
    ID  integer \
    NAME char(100) \
    CITY char(50) 

The syntax of the second form is:

INFX_DEF <tableName> \
    INFX_SQL <sqlStatement>

In this form, an arbitrary complete <sqlStatement> will be executed. The statement is passed untouched to the database (and therefore may include non-portable database constructions). The results of the statement will be returned, one row at a time, as features to FME. This form allows the results of complex joins to be returned to FME.

In this example, the results of joining the employee and city tables are returned. All attributes from the two tables will be present on each returned feature. The feature type will be set to complex.

INFX_DEF complex \
	SQL_STATEMENT \
		"SELECT * FROM EMPLOYEE, CITY WHERE EMPLOYEE.CITY = CITY.NAME"

WHERECLAUSE

Required/Optional

Optional

This optional specification is used to limit the rows read by the reader from each table. If a given table has no INFX_WHERE_CLAUSE or INFX_SQL specified in its DEF line, the global <ReaderKeyword>_WHERECLAUSE value, if present, will be applied as the WHERE specifier of the query used to generate the results. If a table’s DEF line does contain its own SQL_WHERE_CLAUSE or SQL_STATEMENT, it will override the global WHERE clause.

The syntax for this clause is:

INFX_WHERECLAUSE <whereClause>

Note that the <whereClause> does not include the word “WHERE.”

The example below selects only the features whose lengths are more than 2000:

INFX_WHERECLAUSE LENGTH > 2000

Workbench Parameter

Where Clause

BEGIN_SQL{n}

Sometimes, you must execute some SQL statements prior to opening a table. For example, it may be necessary to ensure that a view exists before attempting to read from it.

Upon opening a connection to read from a database, the reader looks for the directive <ReaderKeyword>_BEGIN_SQL{n} (for n=0,1,2,...), and executes each such directive’s value as an SQL statement on the database connection.

Multiple SQL commands can be delimited by a character specified using the FME_SQL_DELIMITER directive, embedded at the beginning of the SQL block. The single character following this directive will be used to split the SQL block into SQL statements, which will then be sent to the database for execution. Note: Include a space before the character.

For example:

FME_SQL_DELIMITER ;
DELETE FROM instructors;
DELETE FROM people
WHERE LastName='Doe' AND FirstName='John'

Multiple delimiters are not allowed and the delimiter character will be stripped before being sent to the database.

Any errors occurring during the execution of these SQL statements will normally terminate the reader or writer (depending on where the SQL statement is executed) with an error. If the specified statement is preceded by a hyphen (“-”), such errors are ignored.

Required/Optional

Optional

Workbench Parameter

Begin SQL

END_SQL{n}

Sometimes you must execute some SQL statements after a set of tables has been read. For example, it may be necessary to clean up a temporary view after creating it in BEGIN_SQL.

Just before closing a connection on a database, the reader looks for the directive <ReaderKeyword>_END_SQL{n} (for n=0,1,2,...), and executes each such directive’s value as an SQL statement on the database connection.

Multiple SQL commands can be delimited by a character specified using the FME_SQL_DELIMITER directive, embedded at the beginning of the SQL block. The single character following this directive will be used to split the SQL block into SQL statements, which will then be sent to the database for execution. Note: Include a space before the character.

For example:

FME_SQL_DELIMITER ;
DELETE FROM instructors;
DELETE FROM people
WHERE LastName='Doe' AND FirstName='John'

Multiple delimiters are not allowed and the delimiter character will be stripped before being sent to the database.

Any errors occurring during the execution of these SQL statements will normally terminate the reader or writer (depending on where the SQL statement is executed) with an error. If the specified statement is preceded by a hyphen (“-”), such errors are ignored.

Required/Optional

Optional

Workbench Parameter

End SQL

IDs

Required/Optional: Optional

This optional specification is used to limit the available and defined database tables that will be read. If no IDs are specified, then all defined and available tables are read. The syntax of the IDs keyword is:

INFX_IDs <featureType1>	\
<featureType2> … \
<featureTypeN> 

The feature types must match those used in DEF lines.

The example below selects only the HISTORY table for input during a translation:

INFX_IDs HISTORY

RETRIEVE_ALL_SCHEMAS

This parameter is applicable only when generating a mapping file, generating a workspace, or when retrieving schemas in an FME Objects application.

When set to yes, schemas for all of the tables and feature classes in the database are returned.

When set to no (or missing), and if RETRIEVE_ALL_TABLE_NAMES is similarly set to no (or missing), only schemas requested by the IDs parameter are returned.

Required/Optional

Optional

Values

YES | NO (default)

NO: The reader will return the schemas for the feature types specified in the IDs. If no features are specified in IDs, then FME returns the schema features for all the tables.

If this value is not specified, then it is assumed to be No.

YES: Indicates to the reader to return all the schemas of the tables in the database.

Mapping File Syntax

Not applicable.

FME Objects applications would include RETRIEVE_ALL_SCHEMAS followed by “YES” in the parameters array passed to IFMEUniversalReader::open().

Workbench Parameter

Not applicable

RETRIEVE_ALL_TABLE_NAMES

This parameter is only applicable when generating a mapping file, generating a workspace or when retrieving schemas in an FME Objects application.

When set to yes, and if RETRIEVE_ALL_SCHEMAS is set to no (or missing), names for all of the tables and feature classes in the database are returned. When set to no (or missing), and if RETRIEVE_ALL_SCHEMAS is similarly set to no (or missing), the schemas requested by the IDs directive are returned.

Note: If RETRIEVE_ALL_SCHEMAS is also set to Yes, then RETRIEVE_ALL_SCHEMAS takes precedence.

Required/Optional

Optional

Values

YES | NO (default)

Mapping File Syntax

Not applicable.

FME Objects applications would include RETRIEVE_ALL_TABLE_NAMES followed by “YES” in the parameters array passed to IFMEUniversalReader::open().

Workbench Parameter

Not applicable (used when you browse a Table List)

SEARCH_ENVELOPE

Using the minimum and maximum x and y parameters, define a bounding box that will be used to filter the input features. Only features that interact with the bounding box are returned.

If all four coordinates of the search envelope are specified as 0, the search envelope will be disabled.

Mapping File Syntax

<ReaderKeyword>_SEARCH_ENVELOPE <minX> <minY> <maxX> <maxY>

Note: If all four coordinates of the search envelope are specified as zero, the search envelope will be disabled.

Required/Optional

Optional

Workbench Parameter

Minimum X, Minimum Y, Maximum X, Maximum Y

SEARCH_ENVELOPE_COORDINATE_SYSTEM

This directive specifies the coordinate system of the search envelope if it is different than the coordinate system of the data.

The COORDINATE_SYSTEM directive, which specifies the coordinate system associated with the data to be read, must always be set if the SEARCH_ENVELOPE_COORDINATE_SYSTEM directive is set.

If this directive is set, the minimum and maximum points of the search envelope are reprojected from the SEARCH_ENVELOPE_COORDINATE_SYSTEM to the reader COORDINATE_SYSTEM prior to applying the envelope.

Required/Optional

Optional

Mapping File Syntax

<ReaderKeyword>_SEARCH_ENVELOPE_COORDINATE_SYSTEM <coordinate system>

Workbench Parameter

Search Envelope Coordinate System

CLIP_TO_ENVELOPE

This directive specifies whether or not FME should clip features to the envelope specified in the SEARCH_ENVELOPE directive.

Values

YES | NO (default)

Mapping File Syntax

<ReaderKeyword>_CLIP_TO_ENVELOPE [yes | no]

Workbench Parameter

Clip To Envelope

EXPOSED_ATTRS

This directive allows the selection of format attributes to be explicitly added to the reader feature type.

This is similar to exposing format attributes on a reader feature type once it has been generated; however, it is even more powerful because it enables schema-driven applications other than Workbench to access and leverage these attributes as if they were explicitly on the schema as user attributes.

The result of picking a list of attributes is a comma-separated list of attribute names and types that will be added to the schema features. Currently all reader feature types will receive the same set of additional schema attributes for a given instance of the reader.

Required/Optional

Optional

Mapping File Syntax

Not applicable.

While it is possible for FME Objects applications to invoke this directive, the required format is not documented.

This directive is intended for use in our GUI applications (for example, Workbench) only.

Workbench Parameter

Additional Attributes to Expose