Reader Directives
The suffixes listed are prefixed by the current <ReaderKeyword> in a mapping file. By default, the <ReaderKeyword> for the MySQL reader is MYSQL_DB_IN.
DATASET
Required/Optional: Required
This specifies the name of the MySQL database. The database must exist in the DBMS. This can be verified by executing the query SHOW DATABASES in the MySQL query interpreter.
Example:
MYSQL_DB_DATASET testdb
Workbench Parameter: Source MySQL Non-Spatial Dataset
HOST
Required/Optional: Required
This specifies the machine running the MySQL DBMS as either an IP address or host name. The database must have proper permissions and be set up to accept TCP/IP connections if connecting from a remote machine.
MYSQL_DB_IN_HOST myserver
Workbench Parameter: Host
PORT
Required/Optional: Required
When connecting remotely, this specifies the TCP/IP port on which to connect to the DBMS service. The default port is 3306.
MYSQL_DB_IN_PORT 3306
Workbench Parameter: Port
USER_NAME
Required/Optional: Required
The name of user who will access the database. The named user must exist with appropriate MySQL permissions. The default user name is mysql.
MYSQL_DB_IN_USER_NAME mysql
Workbench Parameter: User Name
PASSWORD
Required/Optional: Optional
The password of the user accessing the database. This parameter is optional when connecting with a username that has a blank password associated with it.
MYSQL_DB_IN_PASSWORD secret
Workbench Parameter: Password
DEF
Required/Optional: Required
The syntax of the definition is:
MYSQL_DB_DEF <tableName> \ [mysql_where_clause <whereClause>] \ [<fieldName> <fieldType>] +
OR
MYSQL_DB_DEF <queryName> \ [mysql_sql_statement <sqlQuery>]
The <tableName> must match the name of an existing MySQL table in the database. This will be used as the feature type of all the features read from the table. The exception to this rule is when using the sql_statement keyword. In this case, the DEF name may be any valid alphabetic identifier; it does not have to be an existing table name – rather, it is an identifier for the custom SQL query. The feature type of all the features returned from the SQL query are given the query name.
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 exception to this is the geometry field type which is not placed in the DEF.
The definition allows specification of separate search parameters for each table. If any of the per table configuration parameters are given, they will override, for that table, whatever global values have been specified by the reader keywords 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 |
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, then all the tuples are returned. This keyword will be ignored if the sql_statement is present. |
sql_statement |
This specifies an SQL SELECT query to be used as the source for the results. If this is specified, the MySQL reader will execute the query, and use the resulting rows as the features instead of reading from the table <queryName>. All returned features will have a feature type of <queryName>, and attributes for all columns selected by the query. |
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.
The MySQL (Attributes Only) reader allows one to use the sql_statement parameter to specify an arbitrary SQL SELECT query on the DEF line. If this is specified, FME will execute the query, and use each row of data returned from the query to define at least one feature. Each of these features will be given the feature type named in the DEF line, and will contain attributes for every column returned by the SELECT. In this case, all DEF line parameters regarding a WHERE clause or spatial querying are ignored, as it is possible to embed this information directly in the text of the <sqlQuery>.
The following example selects rows from the table ROADS, placing the resulting data into FME features with a feature type of MYROADS. Imagine that ROADS defines a numeric field named ID and a text field named NAME.
MYSQL_DB_DEF MYROADS \ sql_statement ‘SELECT id, name FROM ROADS’
IDs
Required/Optional: Optional
This optional specification is used to limit the available and defined database tables files that will be read. If no IDs are specified, then all defined and available tables are read. The syntax of the IDs keyword is:
MYSQL_DB_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:
MYSQL_DB_IDs ROADS
FETCH_ALL_FEATURES
Required/Optional: Optional
This keyword is used to specify that the entire result set of the main feature query should be retrieved into a large buffer in client memory. Otherwise, the default is to be less memory intensive and to retrieve one row at a time from the server, caching them in a smaller buffer. This allows for large datasets to be processed by default without the possibility of running out of client memory. This keyword can be set to YES to improve the performance of smaller queries.
Workbench Parameter: Fetch All Features At Once
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)