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问:如何显示格式为03-3-13的日期?
解决的方法:
1
Cmd.CommandText = "select * from 支出 where 日期=03-3-13" 中 03-3-13=-13。
日期实际上是Double型数字。0 是 1899-12-30,-13 是 1899-12-17。你当然没有这样日期的记录,所以只有大于才行。
2
Cmd.CommandText = "select * from 支出 where 日期=#03-3-13#"
凡是没有明示,文字型日期是按美国习惯解释的,#03-3-13# 是 0013-03-03。
或者使用长日期格式:
Cmd.CommandText = "select * from 支出 where 日期=#2003-3-13#"
用格式化函数:
Cmd.CommandText = "select * from 支出 where 日期=#" & format(mydate,"yyyy-mm-dd") & "#"
问: 如何判断DNS是否存在?怎样才能列举出所有的DNS?
解决方法:
1、通过利用ODBC API中的SQLDataSource函数可以取得ODBC API中数据源的列表。 判断DNS是否存在:
2、使用API函数Private Declare Function SQLDataSources Lib "ODBC32.DLL" (ByVal henv As Long, ByVal fDirection As Integer, ByVal szDSN As String, ByVal cbDSNMax As Integer, pcbDSN As Integer, ByVal szDescription As String, ByVal cbDescriptionMax As Integer, pcbDescription As Integer) As Integer Private Declare Function SQLAllocEnv Lib "ODBC32.DLL" (ByRef env As Long) As Long 列举出所有DNS。
问:处理文本文件是导入数据库还是直接读写文件呢?
解决方法:
Set main = bumony.OpenRecordset("main") Open App.Path & "\sources\" & Text1.Text & "\′úàíòμ??" & Text1.Text & ".txt" For Input As #1 Do While Not EOF(1) Line Input #1, str1 With main .AddNew !code = Mid(str1, 1, 5) !date = Text1.Text If Mid(str1, 1, 5) = "21310" Or Mid(str1, 1, 5) = "21311" Or Mid(str1, 1, 5) = "21410" Or Mid(str1, 1, 5) = "21411" Then !Money = Trim(Mid(str1, 7, 10)) Else !Money = Trim(Mid(str1, 7, 10)) & "0000" End If !whao = "1102" !ywhao = "1102" .Update End With Loop Close #1 main.Close
问:调用SQL存储后有参数返回,应该怎么赋值?
解决方法:
Dim ADOCmd As New ADODB.Command Dim ADOPrm As New ADODB.Parameter Dim ADORs As ADODB.Recordset '.... Set ADOCmd.ActiveConnection = ADOCon With ADOCmd .CommandType = adCmdStoredProc .CommandText = "ADOTestRPE" End With sParmName = "Output" Set ADOPrm = ADOCmd.CreateParameter(sParmName, adInteger, adParamOutput) ADOCmd.Parameters.Append ADOPrm ADOCmd.Parameters(sParmName).Value = 999 Set ADORs = ADOCmd.Execute '..... Debug.Print "Output: " & ADOCmd.Parameters("Output").Value
问: SQL Server 2000中如何存取图片信息?
解决方法:
新建一个工程,添加 ado 控件,2个 Command ,1个 Picture,1个 Image
Dim Chunk() As Byte Dim lngLengh As Long Dim intChunks As Integer Dim intFragment As Integer Const ChunkSize = 1000 Const lngDataFile = 1 Private Sub cmdBrowse_Click() On Error Resume Next With cmdlFilePath .Filter = "JPG Files|*.JPG|Bitmaps|*.BMP" .ShowOpen txtFilePath.Text = .filename End With End Sub Private Sub Savepic() Open "c:\colordraw0094_m.jpg" For Binary Access Read As lngDataFile lngLengh = LOF(lngDataFile) If lngLengh = 0 Then Close lngDatafile: Exit Sub intChunks = lngLengh \ ChunkSize intFragment = lngLengh Mod ChunkSize 'OpenData 打开数据库 Dim i As Integer Dim rs As New ADODB.Recordset Dim strQ As String If rs.State = adStateOpen Then rs.Close strQ = "Select * From [mydata]" rs.Open strQ, conn, adOpenStatic, adLockOptimistic On Error Resume Next rs.AddNew ReDim Chunk(intFragment) Get lngDataFile, , Chunk() rs.Fields("rs_photo1").AppendChunk Chunk() ReDim Chunk(ChunkSize) For i = 1 To intChunks Get lngDataFile, , Chunk() rs.Fields("rs_photo1").AppendChunk Chunk() Next i rs.Update rs.Close Close lngDataFile Call ShowPic End Sub Public Sub ShowPic() 'OpenData 打开数据库 Dim i As Integer Dim rs As New ADODB.Recordset Dim strQ, filename As String If rs.State = adStateOpen Then rs.Close strQ = "Select * From [mydata]" rs.Open strQ, conn, adOpenStatic, adLockOptimistic If rs.EOF <> True Then rs.MoveLast Else Exit Sub End If On Error Resume Next Open "pictemp" For Binary Access Write As lngDataFile lngLengh = rs.Fields("rs_photo1").ActualSize intChunks = lngLengh \ ChunkSize intFragment = lngLengh Mod ChunkSize ReDim Chunk(intFragment) Chunk() = rs.Fields("rs_photo1").GetChunk(intFragment) Put lngDataFile, , Chunk() For i = 1 To intChunks ReDim Buffer(ChunkSize) Chunk() = rs.Fields("rs_photo1").GetChunk(ChunkSize) Put lngDataFile, , Chunk() Next i Close lngDataFile filename = "pictemp" Picture1.Picture = LoadPicture(filename) Image1.Stretch = True Image1.Picture = Picture1.Picture Kill filename End Sub Private Sub Command1_Click() Savepic End Sub Private Sub Command2_Click() ShowPic End Sub 上面写的是acess的代码!楼主可以改一下连接数据库的设置代码用于sql server!
问:如何在VB里做SQL的数据库的备份和恢复?
解决方法:
Option Explicit Private Const cnstr As String = "Provider=SQLOLEDB.1;Password=****;Persist Security Info=True;" _ & "User ID=*****;Initial Catalog=master;Data Source=******" Private DBCn As ADODB.Connection Private Sub cmdBackup_Click() Set DBCn = New ADODB.Connection DBCn.Open cnstr DBCn.Execute "backup database pubs to disk='d:\pubs_backup.dat'" DBCn.Close End Sub Private Sub cmdRestore_Click() Set DBCn = New ADODB.Connection DBCn.Open cnstr DBCn.Execute "restore database pubs from disk='d:\pubs_backup.dat'" DBCn.Close End Sub 问:如何通过ADO获得数据库的字段名,字段类型? 解决方法: 名: recordset.fields(index).name 类型:recordset.fields(index).type
类型是用数字表示的,msdn上有对应表
---------------------------------------------------------------
OpenSchema 方法
从提供者获取数据库模式信息。
语法
Set recordset = connection.OpenSchema (QueryType, Criteria, SchemaID)
返回值
返回包含模式信息的 Recordset 对象。Recordset 将以只读、静态游标打开。
参数
QueryType 所要运行的模式查询类型,可以为下列任意常量。
Criteria 可选。每个 QueryType 选项的查询限制条件数组,如下所列:
QueryType 值 Criteria 值
AdSchemaAsserts CONSTRAINT_CATALOG CONSTRAINT_SCHEMA CONSTRAINT_NAME AdSchemaCatalogs CATALOG_NAME AdSchemaCharacterSets CHARACTER_SET_CATALOG CHARACTER_SET_SCHEMA CHARACTER_SET_NAME AdSchemaCheckConstraints CONSTRAINT_CATALOG CONSTRAINT_SCHEMA CONSTRAINT_NAME AdSchemaCollations COLLATION_CATALOG COLLATION_SCHEMA COLLATION_NAME AdSchemaColumnDomainUsage DOMAIN_CATALOG DOMAIN_SCHEMA DOMAIN_NAME COLUMN_NAME AdSchemaColumnPrivileges TABLE_CATALOG TABLE_SCHEMA TABLE_NAME COLUMN_NAME GRANTOR GRANTEE adSchemaColumns TABLE_CATALOG TABLE_SCHEMA TABLE_NAME COLUMN_NAME adSchemaConstraintColumnUsage TABLE_CATALOG TABLE_SCHEMA TABLE_NAME COLUMN_NAME adSchemaConstraintTableUsage TABLE_CATALOG TABLE_SCHEMA TABLE_NAME adSchemaForeignKeys PK_TABLE_CATALOG PK_TABLE_SCHEMA PK_TABLE_NAME FK_TABLE_CATALOG FK_TABLE_SCHEMA FK_TABLE_NAME adSchemaIndexes TABLE_CATALOG TABLE_SCHEMA INDEX_NAME TYPE TABLE_NAME adSchemaKeyColumnUsage CONSTRAINT_CATALOG CONSTRAINT_SCHEMA CONSTRAINT_NAME TABLE_CATALOG TABLE_SCHEMA TABLE_NAME COLUMN_NAME adSchemaPrimaryKeys PK_TABLE_CATALOG PK_TABLE_SCHEMA PK_TABLE_NAME adSchemaProcedureColumns PROCEDURE_CATALOG PROCEDURE_SCHEMA PROCEDURE_NAME COLUMN_NAME adSchemaProcedureParameters PROCEDURE_CATALOG PROCEDURE_SCHEMA PROCEDURE_NAME PARAMTER_NAME adSchemaProcedures PROCEDURE_CATALOG PROCEDURE_SCHEMA PROCEDURE_NAME PROCEDURE_TYPE adSchemaProviderSpecific 参见说明 adSchemaProviderTypes DATA_TYPE BEST_MATCH adSchemaReferentialConstraints CONSTRAINT_CATALOG CONSTRAINT_SCHEMA CONSTRAINT_NAME adSchemaSchemata CATALOG_NAME SCHEMA_NAME SCHEMA_OWNER adSchemaSQLLanguages <无> adSchemaStatistics TABLE_CATALOG TABLE_SCHEMA TABLE_NAME adSchemaTableConstraints CONSTRAINT_CATALOG CONSTRAINT_SCHEMA CONSTRAINT_NAME TABLE_CATALOG TABLE_SCHEMA TABLE_NAME CONSTRAINT_TYPE adSchemaTablePrivileges TABLE_CATALOG TABLE_SCHEMA TABLE_NAME GRANTOR GRANTEE adSchemaTables TABLE_CATALOG TABLE_SCHEMA TABLE_NAME TABLE_TYPE adSchemaTranslations TRANSLATION_CATALOG TRANSLATION_SCHEMA TRANSLATION_NAME adSchemaUsagePrivileges OBJECT_CATALOG OBJECT_SCHEMA OBJECT_NAME OBJECT_TYPE GRANTOR GRANTEE adSchemaViewColumnUsage VIEW_CATALOG VIEW_SCHEMA VIEW_NAME adSchemaViewTableUsage VIEW_CATALOG
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