A non-numeric character was found where a numeric was expected
<p>when trying to add new rows I get "A non-numeric character was found where a numeric was expected", should I change one of data types?
Data types in "tables"</p>

<pre><code>CREATE TABLE TITLES
(
TITLE_ID                       VARCHAR2(6) NOT NULL,
TITLE                          VARCHAR2(80) NOT NULL,
CATEGORY                       CHAR(12) NOT NULL, 
PUB_ID                         NUMBER(4) NULL, 
PRICE                          INTEGER NULL,
ADVANCE                        INTEGER NULL,
TOTAL_SALES                    INTEGER NULL,
NOTES                          VARCHAR2(200) NULL, 
PUBDATE                        DATE NOT NULL,
CONTRACT                       INTEGER NOT NULL,
PRIMARY KEY (TITLE_ID),
FOREIGN KEY (PUB_ID) REFERENCES PUBLISHERS(PUB_ID)
);
</code></pre>

<p>Query:</p>

<pre><code>INSERT INTO TITLES (TITLE_ID,TITLE,CATEGORY,PUB_ID,PRICE,ADVANCE,TOTAL_SALES,NOTES,PUBDATE,CONTRACT) VALUES ('PC8888','Secrets of Silicon Valley','popular_comp',1389,20,8000,4095,'Muckraking reporting by two courageous women on the worlds largest computer hardware and software manufacturers.','12-JUN-87',1);
</code></pre>

<p>Error report -
SQL Error: ORA-01858: a non-numeric character was found where a numeric was expected
01858. 00000 -  "a non-numeric character was found where a numeric was expected"
*Cause:    The input data to be converted using a date format model was
           incorrect.  The input data did not contain a number where a number was
           required by the format model.
*Action:   Fix the input data or the date format model to make sure the
           elements match in number and type.  Then retry the operation.</p>