How to delete some data in a table in Hive?

To delete specific data in a Hive table, you can use the DELETE and UPDATE statements in Hive. Deleting particular data from a table: 1. Use the DELETE statement to remove specific rows in a table. For example, to delete rows in a table named table_name that meet specific conditions, you can execute the following statement:

DELETE FROM table_name WHERE condition;

The table_name is the name of the table you want to operate on, and the condition is the criteria for the rows you want to delete. Use the INSERT OVERWRITE statement to write the data that does not need to be deleted to a new table. For example, to write the rows from the table named table_name that do not satisfy a specific condition to a new table named new_table_name, you can execute the following statement:

INSERT OVERWRITE TABLE new_table_name SELECT * FROM table_name WHERE NOT condition;

In this case, new_table_name is the new table name you want to write to, table_name is the table you want to operate on, and condition is the condition for the rows you want to keep. 3. Use the ALTER TABLE statement to rename the original table and rename the new table as the original table. For example, to rename the new table new_table_name as the original table table_name, you can execute the following statement:

ALTER TABLE table_name RENAME TO temp_table_name;
ALTER TABLE new_table_name RENAME TO table_name;

In this case, table_name is the name of the table you want to operate on, and new_table_name is the new name you want to rename it to. Updating part of the data in the table: 1. Use the UPDATE statement to update specific rows in the table. For example, to update rows that meet certain conditions in a table named table_name, you can execute the following statement:

UPDATE table_name SET column1=value1, column2=value2 WHERE condition;

table_name is the name of the table you want to operate on, column1 and column2 are the column names you want to update, value1 and value2 are the values you want to update to, and condition is the condition of the rows you want to update. Please note that DELETE and UPDATE statements are relatively new features in Hive, and may not be applicable to all versions of Hive. Before using these statements, make sure your Hive version supports them. Also, remember to back up your data before executing these statements to prevent accidental data loss.