Hello,

I am fairly new to databases and hopefully have an easy question for
you. I am setting up a database using a program DBDesigner 4. This
database includes some many to many relationships. When I imported
the tables this program created I get an error on the many to many
bridge table in phpMyAdmin. It reads:

! PRIMARY and INDEX keys should not both be set for column
`sd_church_id`

I understand that since sd_contacts_id and sd_worksite_id are PRIMARY
keys they do not need to be INDEX's also. Will removing

INDEX sd_contacts_has_sd_worksite_FKIndex1(sd_contacts_i d),
INDEX sd_contacts_has_sd_worksite_FKIndex2(sd_worksite_i d)

break the many to many relationship or is that unnecessary code?
Thanks!


Here is some SQL this program generated:

CREATE TABLE sd_contacts (
sd_contacts_id INTEGER UNSIGNED NOT NULL AUTO_INCREMENT,
sd_city_id INTEGER UNSIGNED NOT NULL,
first_name VARCHAR(20) NOT NULL,
last_name VARCHAR(20) NOT NULL,
street_address VARCHAR(100) NULL,
postal_code VARCHAR(7) NULL,
phone_number VARCHAR(10) NOT NULL,
mobile_number VARCHAR(10) NULL,
email_address VARCHAR(50) NULL,
PRIMARY KEY(sd_contacts_id),
INDEX sd_contacts_FKIndex1(sd_city_id)
);

CREATE TABLE sd_contacts_has_sd_worksite (
sd_contacts_id INTEGER UNSIGNED NOT NULL,
sd_worksite_id INTEGER UNSIGNED NOT NULL,
PRIMARY KEY(sd_contacts_id, sd_worksite_id),
INDEX sd_contacts_has_sd_worksite_FKIndex1(sd_contacts_i d),
INDEX sd_contacts_has_sd_worksite_FKIndex2(sd_worksite_i d)
);

CREATE TABLE sd_worksite (
sd_worksite_id INTEGER UNSIGNED NOT NULL AUTO_INCREMENT,
sd_city_id INTEGER UNSIGNED NOT NULL,
street_address VARCHAR(50) NULL,
postal_code VARCHAR(7) NULL,
PRIMARY KEY(sd_worksite_id),
INDEX sd_worksite_FKIndex1(sd_city_id)
);