Php reads data from the database and sends it to ios through json

Php reads data from the database and sends it to ios through json. I read the data from the database in php, put the read data into a json string, and then send it to ios, however, I found that all the read data has changed to 1, and then I checked on the php end whether the value of one of the queries is a string that I know. if it is the same, php reads data from the database and sends the data to the ios end through json.
I read the database in php, put the read data into a json string, and then send it to ios, but I found that all the read data has become 1, then, on the php side, I will determine whether one of the queried values is a string I know. if the values are the same, assign a value to this string and then pass it back to the normal string to share it:
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I don't understand. what types of data have all become 1?
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