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23 cze 2013 · I am trying to UPDATE values from a table, but I need to add some conditions. I found the function CASE, but I am not if it is the best method. Here is an example. My table is 'relation': userid1 |
6 paź 2022 · Now that we have a method for identifying the array index at each level of the JSON nested objects, we can try to UPDATE the value: WITH cte AS ( SELECT mytable.id, j.*
If a path identifies an array position past the end of an array, the value is inserted at the end of the array. mysql> SET @j = '["a", {"b": [1, 2]}, [3, 4]]'; mysql> SELECT JSON_ARRAY_INSERT(@j, '$[1]', 'x'); +-----+ | JSON_ARRAY_INSERT(@j, '$[1]', 'x') | +-----+ | ["a", "x", {"b": [1, 2]}, [3, 4]] | +-----+ mysql> SELECT JSON_ARRAY_INSERT(@j ...
16 kwi 2016 · In MySQL, you can use tuple comparison: WHERE (TestId, TestSubId) IN ((10,25), (11,22)) That looks nice and succinct, although, as ypercubeᵀᴹ mentioned in a comment, it may not work well performance-wise.
18 lut 2018 · You can arrange the target values for B.col1 and B.col2 as well as the filtering values for B.col3 as a derived table and join it to B in the UPDATE clause, like this:
26 sty 2024 · The JSON_SET(), JSON_INSERT(), and JSON_REPLACE() functions allow you to update JSON arrays. SET @fruits = JSON_ARRAY('Apple', 'Banana', 'Cherry'); SET @fruits = JSON_INSERT(@fruits, '$[1]', 'Orange'); -- Inserts at position 1 SET @fruits = JSON_SET(@fruits, '$[1]', 'Kiwi'); -- Updates value at position 1 SELECT @fruits;
26 cze 2024 · Updating table rows using subqueries in MySQL enables precise modifications based on specific conditions or values from other tables. This technique leverages subqueries within the SET or WHERE clauses of the UPDATE statement, allowing dynamic and context-specific updates.
