Filtering Data with SQL: Excluding Rows Based on Multiple Conditions in TableA and TableB скачать в хорошем качестве

Filtering Data with SQL: Excluding Rows Based on Multiple Conditions in TableA and TableB

Learn how to filter data in SQL by excluding rows from `TableA` that match specific conditions in `TableB`. This guide includes examples and clear explanations. --- This video is based on the question https://stackoverflow.com/q/77506127/ asked by the user 'Abhishek Kumar' ( https://stackoverflow.com/u/22939121/ ) and on the answer https://stackoverflow.com/a/77506300/ provided by the user 'Gesuele Russello' ( https://stackoverflow.com/u/22842382/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions. Visit these links for original content and any more details, such as alternate solutions, comments, revision history etc. For example, the original title of the Question was: SQL to filter the data from inner query based on 2 conditions Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l... The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license. If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com. --- Filtering Data with SQL: Excluding Rows Based on Multiple Conditions in TableA and TableB In database management, one common task is filtering data to ensure that we only retrieve the information we need. If you're working with multiple tables, this can quickly become a complex challenge. In this guide, we'll tackle a specific problem related to filtering data based on conditions across two tables: TableA and TableB. The Problem You have two tables: TableA, which includes customer data, and TableB, which contains part data. Both tables include Datetime and Partid as common attributes. The challenge is to exclude certain rows from TableA based on specified Partid and Datetime conditions in TableB. Specifically, you aim to: Filter out data from TableA where the Partid falls within a specified range in TableB. Only include Customer ID entries from TableA that relate to Part-A and Part-B and do not share the same Datetime as those in TableB. Example Structure of the Tables Here's a brief overview of the data in each table: TableA Datetime Partid Customer ID 2022-12-24T15:20:00.782Z Part-A CUSTOMER-A 2022-12-24T15:20:00.782Z Part-B CUSTOMER-B ... ... ... TableB Datetime Partid 2022-12-24T15:20:00.782Z Part-A 2022-12-24T15:21:00.782Z Part-B ... ... Desired Output From these tables, the goal is to return the Customer IDs from TableA, while excluding those part entries that match the conditions in TableB. The Solution: SQL Query Breakdown To achieve this result, we can use a Common Table Expression (CTE) in SQL. Here’s the SQL query that addresses our problem: [[See Video to Reveal this Text or Code Snippet]] Explanation of the Query Common Table Expression (CTE): We define a CTE named TableCTE which gathers information from both TableA and TableB. The LEFT JOIN combines these tables on the condition that both Partid and Datetime match. This allows us to include all rows from TableA and any matching rows from TableB. Filtering the Results: In the final SELECT statement, we only return rows from TableCTE where BId is NULL, meaning there was no match in TableB. This effectively filters out any rows from TableA that should be excluded based on the criteria we set regarding Partid and Datetime. Conclusion By applying the CTE and LEFT JOIN, you can elegantly filter out unwanted data entries while retaining the necessary records that satisfy your requirements. This method provides a structured approach to tackle complex data scenarios, making your SQL queries both efficient and effective. For further assistance and best practices in SQL filtering techniques, feel free to explore additional resources or reach out with your questions!