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<html><head><title>SQLite RDBMS</title></head><body bgcolor="#ffffff"><h1>SQLite RDBMS</h1>OGR optionally supports spatial and non-spatial tables stored in SQLite 3.xdatabase files. SQLite is a "light weight" single file based RDBMS enginewith fairly complete SQL semantics and respectible performance. <p>Each table is treated as a layer. Layers with a WKT_GEOMETRYfield will be treated as spatial tables, and the WKT_GEOMETRY column will beread as Well Known Text geometry. <p>Currently the SQLite driver has no support for coordinate systems.<p>The SQLite database is essentially typeless, but the SQLite driver willattempt to classify attributes field as text, integer or floating pointbased on the contents of the first record in a table. None of the listattribute field types existing in SQLite. <p>SQLite databases often due not work well over NFS, or some other networkedfile system protocols due to the poor support for locking. It is safestto operate only on SQLite files on a physical disk of the local system.<p>SQLite is an optionally compiled in driver. It is not compiled in by default.<p>While the SQLite driver supports reading spatial data from records, there isnot support for spatial indexing, so spatial queries will tend to be slow.Attributes queries may be fast, especially if indexes are built for appropriate attribute columns using the "CREATE INDEX <indexname> ON <tablename> ( <columnname> )" SQL command.<p><h2>Creation Issues</h2>The SQLite driver supports creating new SQLite database files, or addingtables to existing ones. Note that a new database file cannot becreated over an existing file. <p><h2>Other Notes</h2><ul><li> Development of the OGR SQLite driver was supported by <a href="http://www.dmsolutions.ca/">DM Solutions Group</a> and <a href="http://www.gomoos.org/">GoMOOS</a>.<p><li> <a href="http://www.sqlite.org/">http://www.sqlite.org</a>: Main SQLite page.<p></ul></body></html>⌨️ 快捷键说明
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