在delphi4.0中如何真正删除dbf文件记录 (2000年11.txt

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在delphi4.0中如何真正删除dbf文件记录 (2000年11月20日) 

本站更新  分类:   作者:dfw  推荐:   阅读次数:527  
(http://www.codesky.net)  

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在delphi4.0中如何真正删除dbf文件记录，DBIPACKTABLE具体如何用(100分) 
问题的分类是：数据库 - 文件型 , 分坛主: SeaSky, 分坛主: yifeng 

来自：sxzww 时间：00-3-11 11:11:10 ID:197921 
我的语句如下：
sql.clear;
SQL.ADD('delete from xz_jybj');
q2.execsql;
close;
执行后，只在数据文件xz_jybj中做了删除标记，
我查询过这个站点关于delete 记录的有关内容，似乎可以用DBIPACKTABLE
函数,但我看不懂,谁能帮助我，谢谢 。





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来自：xWolf 时间：00-3-11 11:37:56 ID:197934 
procedure PackTable(Table: TTable);
var
Props: CURProps;
begin
// 必须以独占方式打开
if (not Table.Active) or (not Table.Exclusive) then Exit;
Check(DBIGetCursorProps(Table.Handle, Props));
// 必须是dBase或FoxPro
if Props.szTableType <> szDBASE then Exit;
Check(DBIPackTable(Table.DBHandle, Table.Handle, nil, szDBASE, True));
Table.Open;
end;



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来自：xWolf 时间：00-3-11 11:47:51 ID:197941 
function DbiPackTable (hDb: hDBIDb; hCursor: hDBICur; pszTableName: PChar; pszDriverType: PChar; bRegenIdxs: Bool): DBIResult stdcall;
参数说明:
hDB: 数据库句柄,可以由TTable.DBHandle得到
hCursor: 数据表关联的游标,若为nil则数据表依赖于pszTableName和pszDriverType
bRegenIdxs决定是否关联外接的索引文件尤其是MDX多索引文件


以下摘自Delphi Help
Example 1: Pack a Paradox or dBASE table.

This example will pack a Paradox or dBASE table therfore removing already deleted rows 
in a table. This function will also regenerate all out-of-date indexes (maintained 
indexes). This example uses the following input:

PackTable(Table1)

The function is defined as follows: 

// Pack a Paradox or dBASE table
// The table must be opened execlusively before calling this function...
procedure PackTable(Table: TTable);
var
Props: CURProps;
hDb: hDBIDb;
TableDesc: CRTblDesc;
begin
// Make sure the table is open exclusively so we can get the db handle...
if not Table.Active then
raise EDatabaseError.Create('Table must be opened to pack');
if not Table.Exclusive then

raise EDatabaseError.Create('Table must be opened exclusively to pack');

// Get the table properties to determine table type...
Check(DbiGetCursorProps(Table.Handle, Props));

// If the table is a Paradox table, you must call DbiDoRestructure...
if Props.szTableType = szPARADOX then begin
// Blank out the structure...
FillChar(TableDesc, sizeof(TableDesc), 0);
// Get the database handle from the table's cursor handle...

Check(DbiGetObjFromObj(hDBIObj(Table.Handle), objDATABASE, hDBIObj(hDb)));
// Put the table name in the table descriptor...
StrPCopy(TableDesc.szTblName, Table.TableName);
// Put the table type in the table descriptor...
StrPCopy(TableDesc.szTblType, Props.szTableType);
// Set the Pack option in the table descriptor to TRUE...
TableDesc.bPack := True;
// Close the table so the restructure can complete...
Table.Close;
// Call DbiDoRestructure...

Check(DbiDoRestructure(hDb, 1, @TableDesc, nil, nil, nil, False));
end
else
// If the table is a dBASE table, simply call DbiPackTable...
if (Props.szTableType = szDBASE) then
Check(DbiPackTable(Table.DBHandle, Table.Handle, nil, szDBASE, True))
else
// Pack only works on PAradox or dBASE; nothing else...
raise EDatabaseError.Create('Table must be either of Paradox or dBASE ' +

'type to pack');

Table.Open;

end;



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来自：sxzww 时间：00-3-11 15:36:04 ID:198012 
接受答案了.
 
 


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