给定一张桌子:
desc SOL_3_ARTIFACTS
Name Null Type
---- ---- -------------
DATA BLOB
ID VARCHAR2(100)
如果我需要使用 SQL*plus 将 BLOB 列的内容读取为 VARHR2,我需要这样的语句:
select UTL_RAW.CAST_TO_VARCHAR2(dbms_lob.substr(lob_loc,2000,1))
from SOL_3_ARTIFACTS where ID = 'RETAILPOOLS'
有人会告诉我如何获取特定行(ID = 'RETAILPOOLS')的 lob_loc(即 DATA 列的定位器)吗?
根据 Belayer 的建议,我运行以下操作但出现错误:
DECLARE
fil BFILE;
pos INTEGER;
amt BINARY_INTEGER;
buf RAW(40);
BEGIN
SELECT SOL_3_ARTIFACTS.DATA INTO fil from SOL_3_ARTIFACTS where ID = 'RETAILPOOLS';
dbms_lob.open(fil, dbms_lob.lob_readonly);
amt := 40; pos := 1 + dbms_lob.getlength(fil); buf := '';
dbms_lob.read(fil, amt, pos, buf);
dbms_output.put_line('Read F1 past EOF: '||
utl_raw.cast_to_varchar2(buf));
dbms_lob.close(fil);
exception
WHEN no_data_found
THEN
BEGIN
dbms_output.put_line('End of File reached. Closing file');
dbms_lob.fileclose(fil);
-- or dbms_lob.filecloseall if appropriate
END;
END;
Error report -
ORA-06550: line 7, column 13:
PL/SQL: ORA-00932: inconsistent datatypes: expected FILE got BLOB
ORA-06550: line 7, column 6:
PL/SQL: SQL Statement ignored
ORA-06550: line 8, column 25:
PLS-00201: identifier 'DBMS_LOB' must be declared
ORA-06550: line 8, column 6:
PL/SQL: Statement ignored
ORA-06550: line 9, column 28:
PLS-00201: identifier 'DBMS_LOB' must be declared
ORA-06550: line 9, column 17:
PL/SQL: Statement ignored
ORA-06550: line 10, column 6:
PLS-00201: identifier 'DBMS_LOB' must be declared
ORA-06550: line 10, column 6:
PL/SQL: Statement ignored
ORA-06550: line 13, column 6:
PLS-00201: identifier 'DBMS_LOB' must be declared
ORA-06550: line 13, column 6:
PL/SQL: Statement ignored
ORA-06550: line 19, column 10:
PLS-00201: identifier 'DBMS_LOB' must be declared
ORA-06550: line 19, column 10:
PL/SQL: Statement ignored
06550. 00000 - "line %s, column %s:\n%s"
*Cause: Usually a PL/SQL compilation error.
*Action: