![]() If you alter the tables or views referenced by the non-schema-bound view, the view’s metadata becomes outdated.If the columns of tables and other views referenced by a non-schema-bound view are renamed, dropped, added, and so on, the metadata of the view becomes irrelevant.Here is the explanation of possible scenarios: Generally, it happens due to changes in a database. Metadata for non-schema-bound views can become outdated for several reasons. Perform the database and metadata refresh.Use manual restore for the database refresh.Common methods for the database refresh.Performance optimization: Database refresh can be a part of the process to improve database performance.Disaster recovery: Critical situations may require an emergency response, including database restoration from backups.This approach guarantees that each test stage starts with a stable and well-defined database state. Testing: In test and development environments, a database is usually reset to a particular state before running tests or developing new features.This helps in identifying bottlenecks faster and facilitates their resolution. Data rollback: If there are some errors, there is a need to revert a database to a previous state.Data update: Sometimes, it’s necessary just to update data in a database to maintain consistent information.Let’s review some cases where you might need to refresh a database: In this tutorial, you have learned how to use the CAST() and TO_DATE() functions to convert a string to a date in SQL.The term “database refresh” typically means the process of resetting or renewing a database to a required state. Notice that the date format must be corresponding to the date string as specified in the statement DD MON YYYYĬheck it out the Oracle TO_DATE() and PostgreSQL TO_DATE() functions for the details. ![]() The following shows the TO_DATE() function syntax: TO_DATE(string, format)įor example, to convert the string '' to a date value, you use the following statement: SELECT TO_DATE( '', 'DD MON YYYY' ) Oracle and PostgreSQL provide the TO_DATE() function that converts a string to date based on a specified format. ![]() Here is the result: Code language: SQL (Structured Query Language) ( sql ) Convert string to date using TO_DATE() function Similarly, the following example also converts the string 180101 to January 1st, 2018: SELECT CAST( '180101' AS DATE) SQL Server converts the string 2018 to January 1st, 2018: The following example shows how to convert a string to a date: SELECT CAST( '2018' AS DATE) In case the function fails to convert, it issues an error, depending on the implementation of a specific database system. The CAST() function returns a DATE value if it successfully converts the string to date. In this syntax, the string can be any DATE value that is convertible to a date. The following illustrates the syntax of the CAST() function: CAST (string AS DATE)Ĭode language: SQL (Structured Query Language) ( sql ) SQL provides a CAST() function that allows you to convert a string to a date. Convert string to date using CAST() function Summary: in this tutorial, you will learn various functions that convert a string to a date in SQL.
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