Foreign Key constraint problem while using InnoDB

[aayush bhatnagar`]

Hello list,

I have seen a thread on my problem here: http://forums.mysql.com/read.php?22,19755,19755

But it could not solve my issue. Hence i am posing my issue here. I am getting a MySQL errno 150.

Let me explain my problem and my table structure:

The tables i have are as follows (these lines are part of my script i execute):

1.CREATE TABLE DATASOURCE_APPUSAGES(APPUSAGE_ID VARCHAR(255) NOT NULL)ENGINE= INNODB;

2. CREATE TABLE DATASOURCE_COLLECTIONS(COLLECTION_NAME VARCHAR(255) NOT NULL,APPUSAGE_ID VARCHAR(255) NOT NULL)ENGINE = INNODB;

3.CREATE TABLE DATASOURCE_DOCUMENTS(DOCUMENT_NAME VARCHAR(255) NOT NULL,XML LONGTEXT NOT NULL,ETAG VARCHAR(255) NOT NULL,COLLECTION_NAME VARCHAR(255) NOT NULL,APPUSAGE_ID VARCHAR(255) NOT NULL)ENGINE=INNODB;

.....and then i do this..

4. ALTER TABLE DATASOURCE_APPUSAGES ADD PRIMARY KEY(APPUSAGE_ID);

5. ALTER TABLE DATASOURCE_COLLECTIONS ADD CONSTRAINT FKB9AD1399A561EB37 PRIMARY KEY(COLLECTION_NAME,APPUSAGE_ID);

6. ALTER TABLE DATASOURCE_COLLECTIONS ADD FOREIGN KEY(APPUSAGE_ID) REFERENCES DATASOURCE_APPUSAGES(APPUSAGE_ID);

7. ALTER TABLE DATASOURCE_DOCUMENTS ADD CONSTRAINT FK1F46F5BCA7B5E21 PRIMARY KEY(DOCUMENT_NAME,COLLECTION_NAME,APPUSAGE_ID);

8. ALTER TABLE DATASOURCE_DOCUMENTS ADD FOREIGN KEY(APPUSAGE_ID) REFERENCES DATASOURCE_COLLECTIONS(COLLECTION_NAME,APPUSAGE_ID);

I get the error on Line-8 during the script execution: MySQL errno:150.

Any help is appreciated..

Thanks in advance

aayush.