在Spark 3.0中,已被取代的方法SQLContext.createExternalTable已被取代,並SparkSession.createExternalTable已移除,以取代它們。createTable 在Spark 3.0中,組態spark.sql.crossJoin.enabled會變成內部組態,且預設為 true,因此根據預設,Spark 不會在 SQL 上引發隱含交叉聯結的例外狀況。
Databricks SQL Databricks Runtime 11.3 LTS 及更高版本 删除Delta Lake 表中的一列或多列或字段。 删除列或字段时,必须删除相关检查约束和生成的列。 有关要求,请参阅使用 Delta Lake 列映射重命名和删除列。 语法 复制 DROP [COLUMN | COLUMNS] [ IF EXISTS ] ( { {column_identifier | f...
DESCRIBE TABLE DESCRIBE VOLUME 列表 SHOW ALL IN SHARE SHOW CATALOGS SHOW COLUMNS 显示连接 SHOW CREATE TABLE SHOW CREDENTIALS SHOW DATABASES SHOW FUNCTIONS SHOW GROUPS SHOW LOCATIONS SHOW PARTITIONS SHOW PROVIDERS SHOW RECIPIENTS SHOW SCHEMAS SHOW SHARES SHOW SHARES IN PROVIDER SHOW TABLE EXTENDED SHOW ...
DESCRIBE TABLE DESCRIBE VOLUME 列表 SHOW ALL IN SHARE SHOW CATALOGS SHOW COLUMNS 显示连接 SHOW CREATE TABLE SHOW CREDENTIALS SHOW DATABASES SHOW FUNCTIONS SHOW GROUPS SHOW LOCATIONS SHOW PARTITIONS SHOW PROVIDERS SHOW RECIPIENTS SHOW SCHEMAS SHOW SHARES ...
Spark SQL 表的命名方式是db_name.table_name,只有数据库名称和数据表名称。如果没有指定db_name而直接引用table_name,实际上是引用default 数据库下的表。在Spark SQL中,数据库只是指定表文件存储的路径,每个表都可以使用不同的文件格式来存储数据,从这个角度来看,可以把database看作是Databricks 表的上层目录,用于...
1. CLONE: Create a copy of the table with a CREATE TABLE LOCATION '<location>' AS SELECT * FROM command.2. SYNC_AS_EXTERNAL, synchronize the table metadata to UC with the SYNC command. Warning: If the managed Hive metastore table is dropped, the drop deletes the underlying data ...
sql("DROP TABLE IF EXISTS flights")) display(spark.sql("CREATE TABLE flights USING DELTA LOCATION '/tmp/flights_delta'")) display(spark.sql("OPTIMIZE flights")) # DBTITLE 1,Step 4 : Rerun the query from Step 2 and observe the latency flights_delta = spark.read.format("delta").load(...
Databricks SQL or Spark SQL Queries to Process Values in JSON String Columns Copy Data into Delta Tables in Databricks SQL Warehouse Insert or Merge Spark SQL or Databricks SQL Query Results or View into Delta Tables Merge Spark SQL or Databricks SQL Query Results and Data from Delta Table with...
A description for the table. Will be set using the SQL COMMENT command, and should show up in most query tools. See also thedescriptionmetadata to set descriptions on individual columns. preactionsNoNo default This can be a;separated list of SQL commands to be executed before loadingCOPYcommand...
从Delta Lake 1.2 开始,您可以删除列,请参阅最新的 ALTER TABLE 文档。 如果您对可以在本地运行的代码段感兴趣,这是一个完整的示例: # create a Delta Lake columns = ["language","speakers"] data = [("English", "1.5"), ("Mandarin", "1.1"), ("Hindi", "0.6")] rdd = spark.sparkContext...