Search results
2 days ago · A UNION type (not to be confused with the SQL UNION operator) is a nested type capable of holding one of multiple "alternative" values, much like the union in C. The main difference being that these UNION types are tagged unions and thus always carry a discriminator "tag" which signals which alternative it is currently holding, even if the inner value itself is null. UNION types are thus more similar to C++17's std::variant, Rust's Enum or the "sum type" present in most functional languages ...
Jun 29, 2024 · If multiple UNION ALL operations exist, use parentheses to specify the priorities of the UNION ALL operations. If UNION is followed by a CLUSTER BY, DISTRIBUTE BY, SORT BY, ORDER BY, or LIMIT clause and odps.sql.type.system.odps2 is set to false, the clause works only on the last select_statement of UNION. If odps.sql.type.system.odps2 is set ...
Jun 8, 2024 · Code Explanation: The said query in SQL that retrieves the ID, name, and "Salesman" or "Customer" label for all salespeople and customers located in London. The results are combined using the UNION operator to create a single set of results. The WHERE clause filters the results to only include rows where the city column equals 'London' for the ...
5 days ago · create table MyTable2 ( a int, b bigint, c varchar, d int ); -- Original SQL statement: select a, sum(b), max(c) from ( select a, b, c from MyTable union all select a, b, c from MyTable2 ) group by a; -- Change the order of input queries in UNION ALL. After this modification, the job remains fully compatible with the state data.
Jun 8, 2024 · 9. From the following table, write a SQL query to find those salespersons and customers who have placed more than one order. Return ID, name. Sample Output: The said query in SQL which selects customer_id and cust_name columns from the customer table and renames them as "ID" and "NAME" respectively. The subquery checks whether at least one ...
Jun 8, 2024 · The SQL UNION ALL operator is used to combine the result sets of two or more SELECT statements into a single result set. Unlike the UNION operator, which removes duplicate rows, UNION ALL retains all rows, including duplicates. Each SELECT statement within the UNION ALL must have the same number of fields in the result sets with similar data types.
6 days ago · 1. The SQL COUNT (), AVG (), and SUM () functions are essential aggregate functions used in SQL for data analysis and reporting. 2. The COUNT () function provides the number of rows that match a specified condition, while the AVG () function calculates the average value of a numeric column, and the SUM () function returns the total sum of a ...
