You won’t be able to do this with meta. All user meta is stored in the meta_value column of wp_usermeta, so if you tried to set a constraint on that column you’d just prevent any other user meta from being set.
Related Posts:
- wpdb->insert: do I need to prepare against SQL injection?
- How do I check for a duplicate record before inserting using wpdb
- WPDB prepare – like % – placeholders?
- $wpdb->update multiple rows, like IN in normal SQL
- Matching database content types to PHP types
- Avoiding “Usage of a direct database call is discouraged”
- dbDelta does not create Table, but returns success
- passing variables as parameters to stored procedures via wpdb from php-script
- Quotes in table name
- How Can I Use $wpdb in PayPal IPN file?
- $wpdb->query() multiple query support
- Is there a (better) way to access $wpdb results?
- Set media metadata (i.e. “dimensions” field) on SVG file after extracting it with a filter
- how to execute different sql query in non-sanitized $wpdb->get_results function
- $wpdb not returning data
- $wpdb Query Result not coming but in phpmyadmin it works [closed]
- WPDB update row with != in where clause
- How to email user after inserting the username in database in WordPress
- Join inside a wpdb query.. confused!
- How to fetch an array in $wpdb?
- Why doesn’t my insert query work?
- Need help writing a $wpdb query
- How to prevent $wpdb->prepare stripping a leading zero in variable value?
- Generate a unique hash/number for tracking on $wpdb insert
- $wpdb->insert query changes to SHOW COLUMNS query Output
- wpdb->insert and stripslashes against sql injection
- Rolling Back from current WordPress version to previous one
- $wpdb select query by month, post type, and taxonomy term
- WPDB – How to search a column in a table
- using $wpdb to insert a form into a post
- wp_create_user not properly entering password
- Constructing a dynamic WPDB query with multiple LIKEs
- How to display user_nicename and usermeta values by custom query in WordPress?
- Foreach loop not working as expected – custom tables and references while submitting a form
- Query insert query executing multiple times
- Undefined offset: 0
- Connect to separate database using $wpdb and authenticate user
- How to access PostgreSQL using WPDB?
- How can I combine one field using wpdb and group by?
- how to use $wpdb->prepare to update a custom table
- $wpdb not being defined in function: Fatal error: Call to a member function query() on a non-object
- How to obtain a reference to $table_prefix in $wpdb object
- Trying to Connect to different database
- how to assign content to a different author while loading content
- Why does this WPDB code throw an empty WPDB error? [closed]
- wordpress $wpdb works only once
- get_results not returning anything
- WordPress core code contains things marked as deprecated by… WordPress?
- $wpdb – joining shows no result
- Compare transient data with a meta box value
- Register custom table for WP to use in a plugin
- wpdb->get_row is selecting the variable as a column name
- CREATE TABLE with dbDelta does not create table
- WordPress “wpdb->update” – Append Text Value
- Display category names on edit user profile using $wpdb
- Get unique results from this function
- Need help converting get_user_meta [keys] into own array
- wpdb and acf via wp rest api
- WPDB SQL Ignore `post_status` Parameter
- WPDB Table Does Not Exist
- Inserting a MySQL record into a table with an array of field names and an array of values
- Incorrect Use of wpdb::prepare()
- wpquery properties last_query and last_result : should these be public or private?
- Ascending order of yearly archives [closed]
- check that the data exists before sending it to wpdb
- $wpdb->get_results(…) with $wpdb->prepare(…) returns empty array despite correct query
- wpdb insert formatting for date in array
- wpdb->insert with special chars failing with collation utf8mb4_unicode_520_ci
- no result returns when using $wpdb->get_results with where clause
- Access to numerically indexed array in wpdb Class and undefined offset
- $wpbd->insert() does not insert user data
- Why $wpdb->insert and $wpdb->update not working server but it is working in localhost?
- wpdb prepare placeholders for MySQL keywords
- Sql query triggered twice
- $wpdb select returns empty array
- Show error messages to a user when database insert fails
- Debugging db calls: $wpdb->insert works on test site, not on identical production site
- Intermittent problem writing update_user_meta
- How to use WHERE NOT EXISTS query to avoid duplicate entry using $wpdb to save in custom table?
- Combine posts and postmeta
- wpdb get_row database query inquiry
- Depreciated Call -> Function wpdb::escape()
- How do I update post based on meta_key in another table?
- wpdb insert working in one function, but not another
- Inserting and updating rows with wpdb indreases integer fields by 1 point sometimes
- Retrieve a list of users based on some conditions
- wp_commentdata: error in documentation?
- Echo only gives me the first part of string
- wp-postratings: list current user’s unrated posts
- esc_sql inserting weird chars to DB
- Error inserting row into table
- Retriving array size from serialized data
- How to update user profile or inputing any data to the wp db from external site?
- Can’t get expected result from a wpdb query
- Get comments after specific date
- get only 1 wpdb and get taxonomy, post to next page [closed]
- Query Problem in Clustom Plugin
- query_vars doesn’t return query string (trying to get data from $wpdb)
- WPDB prepare – like % – placeholders?
- $wpdb->prepare UPDATE process not work in functions.php