ORA-06502:PL/SQL :numberic or value error: character string buffer too small

今天遇到一个错误提示：ORA-06502:PL/SQL :numberic or value error: character string buffer too small，一般对应的中文信息为：ORA-06502: PL/SQL: 数字或值错误 :字符串缓冲区太小。仔细检查调试过程中才发现是开发人员定义了一个变量，但是在脚本里面赋予了该变量超过其长度的值。结果就报这个错误。我习惯总结每一个遇到的错误信息，既有利于学习、总结知识，也方便以后遇到此类问题能够及时给出解决方法。

 

如果执行oerr ora 06502命令，没有提及详细原因(Cause)以及解决方法（Action）。这个估计是出现这类错误的场景太多了的缘故。

$ oerr ora 06502

06502, 00000, "PL/SQL: numeric or value error%s"

// *Cause:

// *Action:

在官方文档http://docs.oracle.com/cd/E11882_01/appdev.112/e25519/datatypes.htm，我看到了关于ORA-06502的错误的一些出现场景。非常有意思。有兴趣的最好直接阅读源文档。

1: 赋值或插入超过长度的值。

Assigning or Inserting Too-Long Values

If the value that you assign to a character variable is longer than the maximum size of the variable, an error occurs. For example:

DECLARE

c VARCHAR2(3 CHAR);

BEGIN

c := 'abc ';

END;

/

Result:

DECLARE

*

ERROR at line 1:

ORA-06502: PL/SQL: numeric or value error: character string buffer too small

ORA-06512: at line 4

2: 违反了SIMPLE_INTEGER Subtype约束

PLS_INTEGER and its subtypes can be implicitly converted to these data types:

·

· CHAR

·

· VARCHAR2

·

· NUMBER

·

· LONG

All of the preceding data types except LONG, and all PLS_INTEGER subtypes, can be implicitly converted to PLS_INTEGER.

A PLS_INTEGER value can be implicitly converted to a PLS_INTEGER subtype only if the value does not violate a constraint of the subtype. For example, casting the PLS_INTEGER value NULL to the SIMPLE_INTEGER subtype raises an exception, as Example 3-5 shows.

Example 3-5 Violating Constraint of SIMPLE_INTEGER Subtype

DECLARE

a SIMPLE_INTEGER := 1;

b PLS_INTEGER := NULL;

BEGIN

a := b;

END;

/

Result:

DECLARE

*

ERROR at line 1:

ORA-06502: PL/SQL: numeric or value error

ORA-06512: at line 5

3: User-Defined Constrained Subtype Detects Out-of-Range Values

Example 3-7 User-Defined Constrained Subtype Detects Out-of-Range Values

DECLARE

SUBTYPE Balance IS NUMBER(8,2);

checking_account Balance;

savings_account Balance;

BEGIN

checking_account := 2000.00;

savings_account := 1000000.00;

END;

/

Result:

DECLARE

*

ERROR at line 1:

ORA-06502: PL/SQL: numeric or value error: number precision too large

ORA-06512: at line 9

4: Implicit Conversion Between Constrained Subtypes with Same Base Type

A constrained subtype can be implicitly converted to its base type, but the base type can be implicitly converted to the constrained subtype only if the value does not violate a constraint of the subtype (see Example 3-5).

A constrained subtype can be implicitly converted to another constrained subtype with the same base type only if the source value does not violate a constraint of the target subtype.

Example 3-8 Implicit Conversion Between Constrained Subtypes with Same Base Type

DECLARE

SUBTYPE Digit IS PLS_INTEGER RANGE 0..9;

SUBTYPE Double_digit IS PLS_INTEGER RANGE 10..99;

SUBTYPE Under_100 IS PLS_INTEGER RANGE 0..99;

d Digit := 4;

dd Double_digit := 35;

u Under_100;

BEGIN

u := d; -- Succeeds; Under_100 range includes Digit range

u := dd; -- Succeeds; Under_100 range includes Double_digit range

dd := d; -- Raises error; Double_digit range does not include Digit range

END;

/

Result:

DECLARE

*

ERROR at line 1:

ORA-06502: PL/SQL: numeric or value error

ORA-06512: at line 12

5: Implicit Conversion Between Subtypes with Base Types in Same Family

Example 3-9 Implicit Conversion Between Subtypes with Base Types in Same Family

DECLARE

SUBTYPE Word IS CHAR(6);

SUBTYPE Text IS VARCHAR2(15);

verb Word := 'run';

sentence1 Text;

sentence2 Text := 'Hurry!';

sentence3 Text := 'See Tom run.';

BEGIN

sentence1 := verb; -- 3-character value, 15-character limit

verb := sentence2; -- 5-character value, 6-character limit

verb := sentence3; -- 12-character value, 6-character limit

END;

/

Result:

DECLARE

*

ERROR at line 1:

ORA-06502: PL/SQL: numeric or value error: character string buffer too small

ORA-06512: at line 13