Αποτελέσματα Αναζήτησης
22 Νοε 2018 · Change Column Name/Type/Position/Comment: ALTER TABLE table_name CHANGE [COLUMN] col_old_name col_new_name column_type [COMMENT col_comment] [FIRST|AFTER column_name] Example: CREATE TABLE test_change (a int, b int, c int); // will change column a's name to a1.
24 Νοε 2020 · CHANGE in ALTER TABLE is used to change the name or data type of an existing column or attribute. Syntax: ALTER TABLE <table_name> CHANGE <column_name> <new_column_name> <new_data_type>; Command: Let’s change the demo_name attribute to customer_name. ALTER TABLE customer CHANGE demo_name customer_name STRING; 4.
This chapter explains how to alter the attributes of a table such as changing its table name, changing column names, adding columns, and deleting or replacing columns.
21 Απρ 2022 · Apache Hive allows us to change the column names similar to many RDBMSs. Let’s see how the user-defined and system-generated column names can be modified. If the user-defined column name: Syntax: ALTER TABLE table_name CHANGE [COLUMN] col_old_name col_new_name column_type [COMMENT col_comment] [FIRST|AFTER column_name] Example: Table Creation:
25 Δεκ 2019 · Uses of Hive ALTER TABLE Command. Below are the most common uses of the ALTER TABLE command: You can rename table and column of existing Hive tables. You can add new column to the table. Rename Hive table column. Add or drop table partition. Add Hadoop archive option to Hive table. Related reading: Apache Hive Data Types and Best Practices
20 Απρ 2017 · Is there a way to change column names in a hive table using first row in the CSV? I know I can skip the first row through skip.header property but I would rather like to set column names using this so as to be able to have right names in the table if the structure of CSV ever changes.
25 Μαρ 2019 · you can use the following syntax. ALTER TABLE table_name [PARTITION partition_spec] CHANGE [COLUMN] col_old_name col_new_name column_type. [COMMENT col_comment] [FIRST|AFTER column_name] [CASCADE|RESTRICT]; As this is an external table, you can drop the table and re-create again with specific changes.
