CREATE TABLE USRBASE.TLKPCONSTRAINTERRORMSG
(
  FLDCONSTRAINTERRORMSGID  NUMBER(11)           NOT NULL,
  FLDOWNER                 VARCHAR2(30 BYTE)    NOT NULL,
  FLDTABLENAME             VARCHAR2(30 BYTE)    NOT NULL,
  FLDCONSTRAINTNAME        VARCHAR2(30 BYTE)    NOT NULL,
  FLDERRORTITLE            VARCHAR2(256 BYTE)   NOT NULL,
  FLDERRORMSG              VARCHAR2(2048 BYTE)  NOT NULL,
  FLDDFU                   DATE                 DEFAULT SYSDATE               NOT NULL,
  FLDUFU                   VARCHAR2(30 BYTE)    DEFAULT USER                  NOT NULL,
  FLDDLU                   DATE                 DEFAULT SYSDATE               NOT NULL,
  FLDULU                   VARCHAR2(30 BYTE)    DEFAULT USER                  NOT NULL
);

   FUNCTION GetConstraintValidation(pcOwner             usrBase.tlkpConstraintErrorMsg.fldOwner%TYPE
                                  , pcTableName         usrBase.tlkpConstraintErrorMsg.fldTableName%TYPE
                                  , pcConstraintName    usrBase.tlkpConstraintErrorMsg.fldConstraintName%TYPE)
      RETURN VARCHAR2
   IS
      cSearchCondition       ALL_CONSTRAINTS.SEARCH_CONDITION%TYPE;
      cErrorTitle            usrBase.tlkpConstraintErrorMsg.fldErrorTitle%TYPE;
      cErrorMsg              usrBase.tlkpConstraintErrorMsg.fldErrorMsg%TYPE;
      cDynamicSql            VARCHAR2(1024);

   BEGIN
      SELECT a.SEARCH_CONDITION
           , m.fldErrorTitle
           , m.fldErrorMsg
        INTO cSearchCondition
           , cErrorTitle
           , cErrorMsg
        FROM ALL_CONSTRAINTS a
           , usrBase.tlkpConstraintErrorMsg m
       WHERE     a.OWNER = m.fldOwner
             AND a.CONSTRAINT_NAME = m.fldConstraintName
             AND a.OWNER = pcOwner
             AND a.CONSTRAINT_NAME = pcConstraintName;

      cSearchCondition := REPLACE(cSearchCondition
                                , 'fld'
                                , ':NEW.fld');

      cDynamicSql := 'SELECT CASE WHEN (' || cSearchCondition || ') THEN -1 ELSE 0 END FROM DUAL';

      RETURN cDynamicSql;

   EXCEPTION
      WHEN excConstraintFailed THEN
         raise_application_error(-20001
                               , CHR(10) || CHR(10) || cErrorTitle || CHR(10) || CHR(10) || cErrorMsg || CHR(10) || CHR(10) || CHR(13));
      WHEN OTHERS THEN
         raise_application_error(-20020
                               , SQLERRM);
   END GetConstraintValidation;

   EXECUTE IMMEDIATE cConstraintValidationSql INTO nValidationResult;

   IF nValidationResult = 0 THEN
      RAISE excConstraintFailed;
   END IF;

SQL> @sample.sql
SQL> CREATE TABLE FUBAR (
  2  ID NUMBER,
  3  COL1 VARCHAR2(8))
  4  /

Table created.

SQL> INSERT INTO FUBAR VALUES(1,'ok');

1 row created.

SQL> 
SQL> UPDATE	 FUBAR set id ='a' where ID=1;
UPDATE	    FUBAR set id ='a' where ID=1
                          *
ERROR at line 1:
ORA-01722: invalid number


SQL> UPDATE	 FUBAR set col1 ='a12345678' where ID=1;
UPDATE	    FUBAR set col1 ='a12345678' where ID=1
                            *
ERROR at line 1:
ORA-12899: value too large for column "SCOTT"."FUBAR"."COL1" (actual: 9,
maximum: 8)

[oracle@vbgeneric ~]$ oerr ora 12514
12514, 00000, "TNS:listener does not currently know of service requested in connect descriptor"
// *Cause:  The listener received a request to establish a connection to a
// database or other service. The connect descriptor received by the listener
// specified a service name for a service (usually a database service)
// that either has not yet dynamically registered with the listener or has
// not been statically configured for the listener.  This may be a temporary
// condition such as after the listener has started, but before the database
// instance has registered with the listener.
// *Action: 
//  - Wait a moment and try to connect a second time.
//  - Check which services are currently known by the listener by executing:
//    lsnrctl services <listener name>
//  - Check that the SERVICE_NAME parameter in the connect descriptor of the
//    net service name used specifies a service known by the listener.
//  - If an easy connect naming connect identifier was used, check that
//    the service name specified is a service known by the listener.
//  - Check for an event in the listener.log file.
[oracle@vbgeneric ~]$