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| + | ====== TerraLib Developer's Guid - Data Access → Drivers → PostGIS ====== | ||
| + | The **PostGIS native data access driver** allows applications to access data stored in a [[http://www.postgresql.org|PostgreSQL]] system with the the geo-spatial extension [[http://postgis.refractions.net/|PostGIS]] enabled. | ||
| + | |||
| + | This section describes the design and implementation issues of this driver and how it can be used by applications. | ||
| + | |||
| + | ===== Design ===== | ||
| + | ===== Creating a PostgreSQL Database ===== | ||
| + | |||
| + | The PostGIS driver allows applications to create new PostgreSQL databases or drop an existing one. | ||
| + | |||
| + | In order to **create a new database** you must specify the connection parameters to an auxiliary database. This database will be used to stablish a temporary connection. All the connection info in the previous section can be used. Besides that information you must specify some parameters for the creation of the new database: | ||
| + | * **PG_NEWDB_NAME:** the name of the new database. (Mandatory) | ||
| + | * **PG_NEWDB_TEMPLATE:** the name of the template database to be used during the creation of the new one. (Mandatory) | ||
| + | * **PG_NEWDB_OWNER:** the owner of the new database. (Optional parameter) | ||
| + | * **PG_NEWDB_ENCODING:** the database encoding. (Optional parameter) | ||
| + | * **PG_NEWDB_TABLESPACE:** the name of the tablespace that will be associated with the new database. (Optional parameter) | ||
| + | * **PG_NEWDB_CONN_LIMIT:** how many concurrent connections can be made to this database. As default in PostgreSQL -1 means no limit. (Optional parameter) | ||
| + | |||
| + | If you intend to connect to the database after its creation with different parameters from the auxiliary database, you must specify new parameters with the prefix: ''PG_NEWDB_''. For instance, if you want a different user to be used in the new data source, you can specify: ''PG_NEWDB_USER'' = ''different-user-name''. All parameters showned in the [[:wiki:documentation:devguide:dataaccess:drivers:postgis#connection_parameters|Connection Parameters section]] can be prefixed. | ||
| + | |||
| + | The code snippet below shows how to create a new POSTGIS database: | ||
| + | <code cpp> | ||
| + | std::map<std::string, std::string> connInfo; | ||
| + | |||
| + | // auxiliary database connection parameters | ||
| + | connInfo["PG_HOST"] = "localhost"; | ||
| + | connInfo["PG_USER"] = "postgres"; | ||
| + | connInfo["PG_PASSWORD"] = "secret"; | ||
| + | connInfo["PG_DB_NAME"] = "postgres"; | ||
| + | |||
| + | // new database parameters | ||
| + | connInfo["PG_NEWDB_NAME"] = "terralib"; | ||
| + | connInfo["PG_NEWDB_TEMPLATE"] = "template1"; | ||
| + | |||
| + | // create new database | ||
| + | std::unique_ptr<te::da::DataSource> pgis(te::da::DataSource::create("POSTGIS", connInfo)); | ||
| + | |||
| + | // the new datasource will in a close state | ||
| + | pgis->open(); | ||
| + | |||
| + | // ... | ||
| + | </code> | ||
| + | |||
| + | ===== Dropping a PostgreSQL Database ===== | ||
| + | |||
| + | To **drop a database** you must specify the connection parameters to an auxiliary database. This database will be used to stablish a temporary connection. All the connection info in the previous section can be used. Besides that information you must specify: | ||
| + | * **PG_DB_TO_DROP:** the name of the database to be dropped. (Mandatory) | ||
| + | |||
| + | The code snippet below shows how to drop an existing PostgreSQL database: | ||
| + | <code cpp> | ||
| + | </code> | ||
| + | |||
| + | ===== Connecting to a PostgreSQL Database ===== | ||
