mysql-5.7

问题 If I have a MySQL table with a JSON column called numbers and a record that has [1, 2, 3] in that column (array of integers), how do I update that record to remove the 2 (so it becomes [1, 3] )? 回答1: I was searching for an answer my self and came to this question, not wanting to use objects I continued the search. But I found a solution, you need to use a combination of json_remove and json_search The following removes the value 1 from the table tbl and the column numbers UPDATE tbl SET

问题 If I have a MySQL table with a JSON column called numbers and a record that has [1, 2, 3] in that column (array of integers), how do I update that record to remove the 2 (so it becomes [1, 3] )? 回答1: I was searching for an answer my self and came to this question, not wanting to use objects I continued the search. But I found a solution, you need to use a combination of json_remove and json_search The following removes the value 1 from the table tbl and the column numbers UPDATE tbl SET

问题 MySQL 5.7 introduces a new file ibtmp1 for storing temporary data in InnoDB to increase the performance. But I have noted that its size increases continuously. On my db server its sizes increases to 92GB. Is there any way of reducing size or deleting the file without restarting the server ? Thanks 回答1: The ibtmp1 once created can't be shrink by any method without restarting mysql service. There are two ways to handle it: Precaution : At the time of server start you should limit the size of

问题 MySQL 5.7 introduces a new file ibtmp1 for storing temporary data in InnoDB to increase the performance. But I have noted that its size increases continuously. On my db server its sizes increases to 92GB. Is there any way of reducing size or deleting the file without restarting the server ? Thanks 回答1: The ibtmp1 once created can't be shrink by any method without restarting mysql service. There are two ways to handle it: Precaution : At the time of server start you should limit the size of

问题 MySQL 5.7 introduces a new file ibtmp1 for storing temporary data in InnoDB to increase the performance. But I have noted that its size increases continuously. On my db server its sizes increases to 92GB. Is there any way of reducing size or deleting the file without restarting the server ? Thanks 回答1: The ibtmp1 once created can't be shrink by any method without restarting mysql service. There are two ways to handle it: Precaution : At the time of server start you should limit the size of

来源： https://stackoverflow.com/questions/64025684/how-to-use-group-by-in-a-query-while-using-variables

来源： https://stackoverflow.com/questions/64025684/how-to-use-group-by-in-a-query-while-using-variables

来源： https://stackoverflow.com/questions/64005360/how-to-achieve-partition-by-kind-of-functionality-using-variables-in-mysql-5-7

问题 How to create index on sub-documents in Json data type in MySQL server? I know we have to create a generated column from the base table and then need to index that column Virtually or stored. But I want syntax for creating a generated column for sub-document. 回答1: JSON columns, like columns of other binary types, are not indexed directly; instead, you can create an index on a generated column that extracts a scalar value from the JSON column. See Section “Secondary Indexes and Generated

问题 I have a table names "campaigns". One of the columns is named "filter_apps" and his type is JSON I have file rows and they just contain array of tokens like so: ["be3beb1fe916ee653ab825fd8fe022", "c130b917983c719495042e31306ffb"] ["4fef3f1999c78cf987960492da4d2a"] ["106c274e319bdeae8bcf8daf515b1f"] ["2521f0df6cffb7487d527319674cf3"] ["c130b917983c719495042e31306ffb"] Examples: SELECT JSON_SEARCH(filter_apps, 'one', 'c130b917983c719495042e31306ffb') FROM campaigns; Result: "$[1]" null null