可选columns可选fulltextThe FULLTEXT modifier indexes the entire column and does not allow prefixing. Works only in MySQL.
可选nameIndex name.
可选nullNULL_FILTERED indexes are particularly useful for indexing sparse columns, where most rows contain a NULL value. In these cases, the NULL_FILTERED index can be considerably smaller and more efficient to maintain than a normal index that includes NULL values.
Works only in Spanner.
可选parserFulltext parser. Works only in MySQL.
可选sparseIf true, the index only references documents with the specified field. These indexes use less space but behave differently in some situations (particularly sorts). This option is only supported for mongodb database.
可选spatialThe SPATIAL modifier indexes the entire column and does not allow indexed columns to contain NULL values. Works only in MySQL and PostgreSQL.
可选synchronizeIndicates if index must sync with database index.
可选uniqueIndicates if this index must be unique or not.
可选whereIndex filter condition.
Index column names.