Question

I need to save a string array to the database but it won’t let me. This is what I have:

 public long createEntry(String startTime, String endTime, String[] states) {
         ContentValues initialValues = new ContentValues();
         initialValues.put(START_KEY_TIME , startTime);
         initialValues.put(END_KEY_TIME , endTime);
         initialValues.put(KEY_STATE, states );

         return databaseConnect.insert(DATABASE_TABLE, null, initialValues);
}

But if I put string[] states in, it says that content values is not able to take an argument. How do I get around that? I was thinking I have 7 things in states, could I like have 7 separate strings and store stuff in each and then afterwards put all the strings back into an string array? Or would that be bad practice?

Answer 1

You cannot save String array into Database. But you can use this trick.

1) So you have to convert it into simple String using convertArrayToString(String[] array) method. This will concatenate all elements of string using ‘comma’.

2) When you would retrieve this String back from Database you could convert it back to String array using convertStringToArray(String str) method. This method will split the string from ‘comma’ and you will get your original array back.

public static String strSeparator = "__,__";
public static String convertArrayToString(String[] array){
    String str = "";
    for (int i = 0;i<array.length; i++) {
        str = str+array[i];
        // Do not append comma at the end of last element
        if(i<array.length-1){
            str = str+strSeparator;
        }
    }
    return str;
}
public static String[] convertStringToArray(String str){
    String[] arr = str.split(strSeparator);
    return arr;
}