Reader Directives
The suffixes listed are prefixed by the current <ReaderKeyword> in a mapping file. By default, the <ReaderKeyword> for the Informix Spatial reader is INFXSPATIAL.
DATASET
Required/Optional: Required
This is the data source name. On Windows, it is an ODBC data source name.
Example:
INFXSPATIAL_DATASET sample
Workbench Parameter: Source IBM Informix Spatial Dataset
USER_NAME
Required/Optional: Required
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:
INFXSPATIAL_USER_NAME bond007
Workbench Parameter: User ID
PASSWORD
Required/Optional: Required
The password to access the database.
Example:
INFXSPATIAL_PASSWORD moneypenny
Workbench Parameter: Password
DEF
Required/Optional: Optional
The syntax of the definition is:
INFXSPATIAL_DEF <tableName> \ [infx_geometry_column <geometryColumn>] \ [infx_where_clause <whereClause>] \ [<fieldName> <fieldType>] +
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 geometry column or columns should not be specified as attributes on the DEF line. Rather, the desired geometry column may be specified in the infx_geometry_column parameter. In the case that infx_geometry_column is not specified and a feature type has more than one registered geometry column or layer, the Informix Spatial Reader will arbitrarily choose one as the primary geometry column.
The <tableName> can be either fully qualified or not. A fully qualified table name consist of two parts separated by a period (.). The first part is the <schema name> and second part is the <table name>. The <table name> part must match a table in the schema specified by the <schema name> part of the <tableName>. If a schema name is not provided as part of the table name, then the username will be considered the schema name. This will be used as the feature type of all the features read from the table. For example, if a user wants to read a table from its own schema then only the table name can be provided, but if the user wants to read from a different user’s schema, then table name should be qualified with schema name.
The definition allows specification of separate search parameters for each table. If any of the configuration parameters are given, they will override, for that table, whatever global values have been specified by the reader directives listed above. If any of these parameters is not specified, the global values will be used.
The following table summarizes the definition line configuration parameters:
Parameter |
Contents |
infx_geometry_column |
This specifies the spatial layer or geometry column to use for reading spatial data in case the table has multiple geometry/spatial columns. |
infx_where_clause |
This specifies the SQL WHERE clause applied to the attributes of the layer’s features to limit the set of features returned. If this is not specified, the value of the <ReaderKeyword>_WHERE_CLAUSE directive is used. |
If no <whereClause> is specified, all rows in the table will be read and returned as individual features. 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”.
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 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.
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
SIMPLIFY_AGGREGATES
Required/Optional: Optional
This directive specifies whether multi-geometry or aggregate features with one member are read as stored or simplified and read as single member. e.g. an aggregate of points or multipoint features with only one point will be returned as a simple point if the value of this directive is YES.
Values: YES | NO
Default value: NO
Example:
The syntax of the SIMPLIFY_AGGREGATES directive is:
INFXSPATIAL_SIMPLIFY_AGGREGATES YES
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 directive is:
INFXSPATIAL_IDs <featureType1> \ <featureType2> \ ... \ <featureTypeN>
The feature types must match those used in DEF lines.
The example below selects only the ROADS table for input during a translation:
INFXSPATIAL_IDs ROADS
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