DBMS_LOB
最近更新时间: 2025-10-11 18:10:00
DBMS_LOB用于在大对象上进行操作。DBMS_LOB包提供了子程序可以在BLOB、CLOB、NCLOB、BFILE和临时LOB上操作的子程序。使用DBMS_LOB可以访问和处理LOB的特定部分或全部
| 存储过程/函数 | 描述 |
| APPEND(dest_lob IN OUT,src_lob) | Appends one large object to another. |
| COMPARE(lob_1, lob_2 [, amount[, offset_1 [, offset_2 ]]]) | Compares two large objects. |
| CONVERTOBLOB(dest_lob IN OUT,src_clob, amount, dest_offsetIN OUT, src_offset IN OUT,blob_csid, lang_context IN OUT,warning OUT) | Converts character data to binary. |
| CONVERTTOCLOB(dest_lob IN OUT,src_blob, amount, dest_offsetIN OUT, src_offset IN OUT,blob_csid, lang_context IN OUT,warning OUT) | Converts binary data to character. |
| COPY(dest_lob IN OUT, src_lob,amount [, dest_offset [,src_offset ]]) | Copies one large object to another. |
| ERASE(lob_loc IN OUT, amount IN OUT [, offset ]) | Erase a large object. |
| GET_STORAGE_LIMIT(lob_loc) | Get the storage limit for large objects. |
| GETLENGTH(lob_loc) | Get the length of the large object. |
| INSTR(lob_loc, pattern [,offset [, nth ]]) | Get the position of the nth occurrence of a pattern in the large object starting atoffset. |
| READ(lob_loc, amount IN OUT,offset, buffer OUT) | Read a large object. |
| SUBSTR(lob_loc [, amount [,offset ]]) | Get part of a large object. |
| TRIM(lob_loc IN OUT, newlen) | Trim a large object to the specified length. |
| WRITE(lob_loc IN OUT, amount,offset, buffer) | Write data to a large object. |
| WRITEAPPEND(lob_loc IN OUT,amount, buffer) | Write data from the buffer to the end of a large object. |
示例：
DBMS_LOB.WRITEAPPEND (
lob_loc IN OUT NOCOPY BLOB,
amount IN INTEGER,
buffer IN RAW);
DBMS_LOB.WRITEAPPEND (
lob_loc IN OUT NOCOPY CLOB CHARACTER SET ANY_CS,
amount IN INTEGER,
buffer IN VARCHAR2 CHARACTER SET lob_loc%CHARSET);
declare
v_clob1 clob;
begin
v_clob1:=to_clob('123456');
dbms_output.put_line(v_clob1);
DBMS_LOB.WRITEAPPEND(v_clob1,3,'789');
dbms_output.put_line(v_clob1);
end;