The following example returns all rows that contain at least one numerical digit in PostgreSQL.
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Database Management Systems
SQLite JSON_TYPE()
The SQLite json_type() function returns the type of the outermost element of the given JSON.
We provide the JSON as an argument when we call the function.
We can optionally pass a path, which allows us to get the type of a specific array element or object member within the JSON.
Continue readingSQLite JSON_QUOTE()
In SQLite, the json_quote() function converts a number or string into its corresponding JSON representation.
We provide the number or string as an argument when we call the function, and the function returns a JSON representation of that value.
Continue readingGenerate INSERT Statements from SQLite Query Results
The SQLite command line interface provides us with the ability to auto-generate SQL INSERT statements from a query. This can be done by changing the output mode to insert.
SQLite JSON_REMOVE()
We can use the SQLite json_remove() function to remove one or more elements from a JSON object or array.
We pass the original JSON as the first argument when we call the function, followed by one or more paths that specify which elements to remove. By “elements”, I mean either array elements or object members (key/value pairs).
Continue readingSQLite JSON_PATCH()
In SQLite, the json_patch() function can be used to add, modify, or delete elements of a JSON Object.
To do this, it runs the RFC-7396 MergePatch algorithm to apply a given patch against the given JSON input.
We pass the original JSON as the first argument when we call the function, followed by the patch. The function then applies that patch against JSON in the first argument.
Continue readingFix “ERROR 3942 (HY000): Each row of a VALUES clause must have at least one column” when using the VALUES Statement in MySQL
If you’re getting an error that reads “ERROR 3942 (HY000): Each row of a VALUES clause must have at least one column” in MySQL, you could have an empty row constructor when using the VALUES statement.
To fix this issue, make sure you’ve got at least one value in each ROW() clause within the VALUES statement.
SQLite JSON_REPLACE()
The SQLite json_replace() function allows us to replace an existing value in a JSON document with another value.
We pass the original JSON as the first argument when we call the function, followed by the path of the value to replace, followed by the value to replace.
We can also replace multiple key/value pairs if required.
Continue readingSQLite JSON_SET()
The SQLite json_set() function allows us to insert into, or replace, a value in a JSON document.
We pass the original JSON as the first argument when we call the function, followed by a path that specifies where to insert/replace the new value, followed by the value to insert/replace.
We can also insert/replace multiple key/value pairs if required.
Continue reading3 Ways to Delete Duplicate Rows in SQL Server while Ignoring the Primary Key
The following examples use T-SQL to delete duplicate rows in SQL Server while ignoring the primary key or unique identifier column.
More specifically, the examples delete duplicate rows but keep one. So, given two identical rows, one is deleted and the other remains. This is often referred to as “de-duping” the table, “deduplication” of the table, etc.
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