title: MySQL:putting constraint on each character of a Column entry of char(n) type
body: <p>I am making a table PATIENT which looks something like following:</p>
  
  <pre><code>CREATE TABLE PATIENT
  (
  PATIENT_ID          integer NOT NULL auto_increment,
  PATIENT_CONTROL_NO  char(10) NOT NULL,
  MEDICAL_RECORD_NO   char(10) NOT NULL,
  PERSON_ID           integer NOT NULL,
  GUARANTOR_ID        integer NOT NULL,
  GUARANTOR_REL_CODE  char(2) NOT NULL,
  TREAT_AUTH_CODE     char(18) NULL,
  ADC_CODE            char(2) NULL,
  CAPPLAN_AMTMONTH        decimal(11,2) NULL,
  PRIMARY KEY (PATIENT_ID,PATIENT_CONTROL_NO,MEDICAL_RECORD_NO),
  check(GUARANTOR_REL_CODE in('01','18','19','20','21','39','40','53','G8'))
  );
  </code></pre>
  
  <p>Now the thing is I want to add the following Constraint(character-wise) in the column "TREAT_AUTH_CODE" which has 18 characters:</p>
  
  <pre><code>CHARACTER_POSITION               CHARACTER_TYPE
     1,2,5,6,9,10                     NUMBERS
     3,4,7,8,11-18                   ALPHABETS
  </code></pre>
  
  <p>Do I have to use the concept of arrays or can it be achieved in some easier way?
  If arrays, help with that too....</p>
  
  <p>Thankx.....</p>