7/26/2023 0 Comments Fminer modify column dataIf the partition is only partially identified a slice of partitions is dropped. Otherwise, non existing partitions will cause an error. When you specify IF EXISTS Azure Databricks will ignore an attempt to drop partitions that do not exists. If specified this clause drops one or more partitions from the table, optionally deleting any files at the partitions’ locations.ĭelta Lake tables do not support dropping of partitions. If there are files present at the location they populate the partition and must be compatible with theĭata_source of the table and its options. If no location is specified the location will be derived from the location of the table and the partition keys. Path must be a STRING literal representing an optional location pointing to the partition. If the partition already exists an error is raised unless IF NOT EXISTS has been specified. The partition keys must match the partitioning of the table and be associated with values. Īn optional clause directing Azure Databricks to ignore the statement if the partition already exists.Ī partition to be added. This clause is not supported for JDBC data sources.Īdds one or more columns to the table, or fields to existing columns in a Delta Lake table. The name must not include a temporal specification. Renames the table within the same schema. If the table cannot be found Azure Databricks raises a TABLE_OR_VIEW_NOT_FOUND error. If you use Unity Catalog you must have MODIFY permission to:Īll other operations require ownership of the table. The cache will be lazily filled when the table or the dependents are accessed the next time. If the table is cached, the command clears cached data of the table and all its dependents that refer to it. To change the comment on a table use COMMENT ON. The following Oracle ALTER TABLE statement would drop the salary column from the employees table: ALTER TABLE employeesĭROP COLUMN salary Practice Exercise #7:īased on the departments table below, rename the department_name column to dept_name.Applies to: Databricks SQL Databricks RuntimeĪlters the schema or properties of a table.įor type changes or renaming columns in Delta Lake see rewrite the data. State varchar2(2)) Practice Exercise #6:īased on the employees table below, drop the salary column. MODIFY (customer_name varchar2(50) NOT NULL, The following Oracle ALTER TABLE statement would modify the customer_name and state columns accordingly in the customers table: ALTER TABLE customers MODIFY employee_name varchar2(75) Practice Exercise #5:īased on the customers table below, change the customer_name column to NOT allow null values and change the state column to a varchar2(2) datatype. The following Oracle ALTER TABLE statement would change the datatype for the employee_name column to varchar2(75): ALTER TABLE employees Last_contacted date) Practice Exercise #4:īased on the employees table below, change the employee_name column to a varchar2(75) datatype. The following Oracle ALTER TABLE statement would add the contact_name and last_contacted columns to the customers table: ALTER TABLE customers CREATE TABLE customersĬONSTRAINT customers_pk PRIMARY KEY (customer_id) The following Oracle ALTER TABLE statement would add a bonus column to the employees table: ALTER TABLE employeesĪDD bonus number(6) Practice Exercise #3:īased on the customers table below, add two columns - one column called contact_name that is a varchar2(50) datatype and one column called last_contacted that is a date datatype. CREATE TABLE employeesĬONSTRAINT employees_pk PRIMARY KEY (employee_number) The following Oracle ALTER TABLE statement would rename the departments table to depts: ALTER TABLE departmentsīased on the employees table below, add a column called bonus that is a number(6) datatype. CREATE TABLE departmentsĬONSTRAINT departments_pk PRIMARY KEY (department_id) Based on the departments table below, rename the departments table to depts.
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