PLS-00108: declarative units must be a single variable declaration
Cause: While checking a declarative unit (a top-level declare block without the BEGIN...END), PL/SQL found that there was more than one item declared or that the item was not a variable declaration. A table is a common variable declaration at the unit level. To define a TABLE, compile a DECLARE compilation unit, but only one at a time is allowed.
Action: Declare variables in separate declarative units.
PLS-00105: at most one forward declaration of type 'string' is permitted
Cause: More than one forward declaration of a type is redundant.
Action: Remove all but one forward declaration.
PLS-00104: empty argument list in call of procedure 'string' must be omitted
Cause: In a subprogram call, the name of the subprogram was followed by an empty parameter list. For example, procedure P was called as P(). This is not allowed.
Action: Remove the empty parameter list. In the example, change the procedure call to P.
PLS-00103: found 'string' but expected one of the following: 'string'"},
Cause: This error message is from the parser. It found a token (language element) that is inappropriate in this context.
Action: Check previous tokens as well as the one given in the error message. The line and column numbers given in the error message refer to the end of the faulty language construct.
PLS-00102: parser stack overflow because nesting is too deep
Cause: The parser, which checks the syntax of PL/SQL statements, uses a data structure called a stack; the number of levels of nesting in the PL/SQL block exceeded the stack capacity.
Action: Reorganize the block structure to avoid nesting at too deep a level. For example, move the lowest-level sub-block to a higher level.