Ang*_*ker 26 ms-access ms-jet-ace
我试图提取.mdb数据库的模式,以便我可以在其他地方重新创建数据库.
我该如何解决这样的问题？
Fio*_*ala 22
使用VBA可以做一点.例如,下面是为具有本地表的数据库创建脚本的开始.
Dim db As Database
Dim tdf As TableDef
Dim fld As DAO.Field
Dim ndx As DAO.Index
Dim strSQL As String
Dim strFlds As String
Dim strCn As String
Dim fs, f
Set db = CurrentDb
Set fs = CreateObject("Scripting.FileSystemObject")
Set f = fs.CreateTextFile("C:\Docs\Schema.txt")
For Each tdf In db.TableDefs
If Left(tdf.Name, 4) <> "Msys" Then
strSQL = "strSQL=""CREATE TABLE [" & tdf.Name & "] ("
strFlds = ""
For Each fld In tdf.Fields
strFlds = strFlds & ",[" & fld.Name & "] "
Select Case fld.Type
Case dbText
'No look-up fields
strFlds = strFlds & "Text (" & fld.Size & ")"
Case dbLong
If (fld.Attributes And dbAutoIncrField) = 0& Then
strFlds = strFlds & "Long"
Else
strFlds = strFlds & "Counter"
End If
Case dbBoolean
strFlds = strFlds & "YesNo"
Case dbByte
strFlds = strFlds & "Byte"
Case dbInteger
strFlds = strFlds & "Integer"
Case dbCurrency
strFlds = strFlds & "Currency"
Case dbSingle
strFlds = strFlds & "Single"
Case dbDouble
strFlds = strFlds & "Double"
Case dbDate
strFlds = strFlds & "DateTime"
Case dbBinary
strFlds = strFlds & "Binary"
Case dbLongBinary
strFlds = strFlds & "OLE Object"
Case dbMemo
If (fld.Attributes And dbHyperlinkField) = 0& Then
strFlds = strFlds & "Memo"
Else
strFlds = strFlds & "Hyperlink"
End If
Case dbGUID
strFlds = strFlds & "GUID"
End Select
Next
strSQL = strSQL & Mid(strFlds, 2) & " )""" & vbCrLf & "Currentdb.Execute strSQL"
f.WriteLine vbCrLf & strSQL
'Indexes
For Each ndx In tdf.Indexes
If ndx.Unique Then
strSQL = "strSQL=""CREATE UNIQUE INDEX "
Else
strSQL = "strSQL=""CREATE INDEX "
End If
strSQL = strSQL & "[" & ndx.Name & "] ON [" & tdf.Name & "] ("
strFlds = ""
For Each fld In tdf.Fields
strFlds = ",[" & fld.Name & "]"
Next
strSQL = strSQL & Mid(strFlds, 2) & ") "
strCn = ""
If ndx.Primary Then
strCn = " PRIMARY"
End If
If ndx.Required Then
strCn = strCn & " DISALLOW NULL"
End If
If ndx.IgnoreNulls Then
strCn = strCn & " IGNORE NULL"
End If
If Trim(strCn) <> vbNullString Then
strSQL = strSQL & " WITH" & strCn & " "
End If
f.WriteLine vbCrLf & strSQL & """" & vbCrLf & "Currentdb.Execute strSQL"
Next
End If
Next
f.Close
Eri*_*c G 11
这是一个古老的问题,但不幸的是多年生:(
我认为这段代码可能对寻找解决方案的其他人有用.它设计为通过cscript从命令行运行,因此无需将代码导入Access项目.与Oliver中的代码类似(并受其启发)如何在Access开发中使用版本控制.
' Usage:
' CScript //Nologo ddl.vbs <input mdb file> > <output>
'
' Outputs DDL statements for tables, indexes, and relations from Access file
' (.mdb, .accdb) <input file> to stdout.
' Requires Microsoft Access.
'
' NOTE: Adapted from code from "polite person" + Kevin Chambers - see:
' http://www.mombu.com/microsoft/comp-databases-ms-access/t-exporting-jet-table-metadata-as-text-119667.html
'
Option Explicit
Dim stdout, fso
Dim strFile
Dim appAccess, db, tbl, idx, rel
Set stdout = WScript.StdOut
Set fso = CreateObject("Scripting.FileSystemObject")
' Parse args
If (WScript.Arguments.Count = 0) then
MsgBox "Usage: cscript //Nologo ddl.vbs access-file", vbExclamation, "Error"
Wscript.Quit()
End if
strFile = fso.GetAbsolutePathName(WScript.Arguments(0))
' Open mdb file
Set appAccess = CreateObject("Access.Application")
appAccess.OpenCurrentDatabase strFile
Set db = appAccess.DBEngine(0)(0)
' Iterate over tables
' create table statements
For Each tbl In db.TableDefs
If Not isSystemTable(tbl) And Not isHiddenTable(tbl) Then
stdout.WriteLine getTableDDL(tbl)
stdout.WriteBlankLines(1)
' Iterate over indexes
' create index statements
For Each idx In tbl.Indexes
stdout.WriteLine getIndexDDL(tbl, idx)
Next
stdout.WriteBlankLines(2)
End If
Next
' Iterate over relations
' alter table add constraint statements
For Each rel In db.Relations
Set tbl = db.TableDefs(rel.Table)
If Not isSystemTable(tbl) And Not isHiddenTable(tbl) Then
stdout.WriteLine getRelationDDL(rel)
stdout.WriteBlankLines(1)
End If
Next
Function getTableDDL(tdef)
Const dbBoolean = 1
Const dbByte = 2
Const dbCurrency = 5
Const dbDate = 8
Const dbDouble = 7
Const dbInteger = 3
Const dbLong = 4
Const dbDecimal = 20
Const dbFloat = 17
Const dbMemo = 12
Const dbSingle = 6
Const dbText = 10
Const dbGUID = 15
Const dbAutoIncrField = 16
Dim fld
Dim sql
Dim ln, a
sql = "CREATE TABLE " & QuoteObjectName(tdef.name) & " ("
ln = vbCrLf
For Each fld In tdef.fields
sql = sql & ln & " " & QuoteObjectName(fld.name) & " "
Select Case fld.Type
Case dbBoolean 'Boolean
a = "BIT"
Case dbByte 'Byte
a = "BYTE"
Case dbCurrency 'Currency
a = "MONEY"
Case dbDate 'Date / Time
a = "DATETIME"
Case dbDouble 'Double
a = "DOUBLE"
Case dbInteger 'Integer
a = "INTEGER"
Case dbLong 'Long
'test if counter, doesn't detect random property if set
If (fld.Attributes And dbAutoIncrField) Then
a = "COUNTER"
Else
a = "LONG"
End If
Case dbDecimal 'Decimal
a = "DECIMAL"
Case dbFloat 'Float
a = "FLOAT"
Case dbMemo 'Memo
a = "MEMO"
Case dbSingle 'Single
a = "SINGLE"
Case dbText 'Text
a = "VARCHAR(" & fld.Size & ")"
Case dbGUID 'Text
a = "GUID"
Case Else
'>>> raise error
MsgBox "Field " & tdef.name & "." & fld.name & _
" of type " & fld.Type & " has been ignored!!!"
End Select
sql = sql & a
If fld.Required Then _
sql = sql & " NOT NULL "
If Len(fld.DefaultValue) > 0 Then _
sql = sql & " DEFAULT " & fld.DefaultValue
ln = ", " & vbCrLf
Next
sql = sql & vbCrLf & ");"
getTableDDL = sql
End Function
Function getIndexDDL(tdef, idx)
Dim sql, ln, myfld
If Left(idx.name, 1) = "{" Then
'ignore, GUID-type indexes - bugger them
ElseIf idx.Foreign Then
'this index was created by a relation. recreating the
'relation will create this for us, so no need to do it here
Else
ln = ""
sql = "CREATE "
If idx.Unique Then
sql = sql & "UNIQUE "
End If
sql = sql & "INDEX " & QuoteObjectName(idx.name) & " ON " & _
QuoteObjectName(tdef.name) & "( "
For Each myfld In idx.fields
sql = sql & ln & QuoteObjectName(myfld.name)
ln = ", "
Next
sql = sql & " )"
If idx.Primary Then
sql = sql & " WITH PRIMARY"
ElseIf idx.IgnoreNulls Then
sql = sql & " WITH IGNORE NULL"
ElseIf idx.Required Then
sql = sql & " WITH DISALLOW NULL"
End If
sql = sql & ";"
End If
getIndexDDL = sql
End Function
' Returns the SQL DDL to add a relation between two tables.
' Oddly, DAO will not accept the ON DELETE or ON UPDATE
' clauses, so the resulting sql must be executed through ADO
Function getRelationDDL(myrel)
Const dbRelationUpdateCascade = 256
Const dbRelationDeleteCascade = 4096
Dim mytdef
Dim myfld
Dim sql, ln
With myrel
sql = "ALTER TABLE " & QuoteObjectName(.ForeignTable) & _
" ADD CONSTRAINT " & QuoteObjectName(.name) & " FOREIGN KEY ( "
ln = ""
For Each myfld In .fields 'ie fields of the relation
sql = sql & ln & QuoteObjectName(myfld.ForeignName)
ln = ","
Next
sql = sql & " ) " & "REFERENCES " & _
QuoteObjectName(.table) & "( "
ln = ""
For Each myfld In .fields
sql = sql & ln & QuoteObjectName(myfld.name)
ln = ","
Next
sql = sql & " )"
If (myrel.Attributes And dbRelationUpdateCascade) Then _
sql = sql & " ON UPDATE CASCADE"
If (myrel.Attributes And dbRelationDeleteCascade) Then _
sql = sql & " ON DELETE CASCADE"
sql = sql & ";"
End With
getRelationDDL = sql
End Function
Function isSystemTable(tbl)
Dim nAttrib
Const dbSystemObject = -2147483646
isSystemTable = False
nAttrib = tbl.Attributes
isSystemTable = (nAttrib <> 0 And ((nAttrib And dbSystemObject) <> 0))
End Function
Function isHiddenTable(tbl)
Dim nAttrib
Const dbHiddenObject = 1
isHiddenTable = False
nAttrib = tbl.Attributes
isHiddenTable = (nAttrib <> 0 And ((nAttrib And dbHiddenObject) <> 0))
End Function
Function QuoteObjectName(str)
QuoteObjectName = "[" & str & "]"
End Function
如果您还想要导出查询定义,这个问题应该有所帮助.它有点不同,因为你通常不用普通的DDL CREATE VIEW foo AS ...语法创建querydef ,事实上我不确定你能不能(？)
但是这里有一小段我编写的用于备份查询以分离.sql文件的脚本(这是用于备份所有前端db代码的更大脚本的一部分,请参阅Oliver 对此问题的回答).
Dim oApplication
Set oApplication = CreateObject("Access.Application")
oApplication.OpenCurrentDatabase sMyAccessFilePath
oApplication.Visible = False
For Each myObj In oApplication.DBEngine(0)(0).QueryDefs
writeToFile sExportpath & "\queries\" & myObj.Name & ".sql", myObj.SQL
Next
Function writeToFile(path, text)
Dim fso, st
Set fso = CreateObject("Scripting.FileSystemObject")
Set st = fso.CreateTextFile(path, True)
st.Write text
st.Close
End Function
以下C#概述了如何从.mdb文件获取架构.
获取与数据库的连接:
String f = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + "database.mdb";
OleDbConnection databaseConnection = new OleDbConnection(f);
databaseConnection.Open();
获取每个表的名称:
DataTable dataTable = databaseConnection.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, new object[] { null, null, null, "TABLE" });
int numTables = dataTable.Rows.Count;
for (int tableIndex = 0; tableIndex < numTables; ++tableIndex)
{
String tableName = dataTable.Rows[tableIndex]["TABLE_NAME"].ToString();
获取每个表的字段:
DataTable schemaTable = databaseConnection.GetOleDbSchemaTable(OleDbSchemaGuid.Columns, new object[] { null, null, tableName, null });
foreach (DataRow row in schemaTable.Rows)
{
String fieldName = row["COLUMN_NAME"].ToString(); //3
String fieldType = row["DATA_TYPE"].ToString(); // 11
String fieldDescription = row["DESCRIPTION"].ToString(); //27
}
}
你在哪里的3,11并27从何而来？我通过DataRow.ItemArray调试器找到它们,有没有人知道'正确'的方式？
如果您乐意使用纯Access SQL之外的其他内容,则可以保留ADOX对象的集合并使用它们来重新创建表结构.
示例(在Python中,当前不会重新创建关系和索引,因为我正在处理的项目不需要它):
import os
import sys
import datetime
import comtypes.client as client
class Db:
def __init__(self, original_con_string = None, file_path = None,
new_con_string = None, localise_links = False):
self.original_con_string = original_con_string
self.file_path = file_path
self.new_con_string = new_con_string
self.localise_links = localise_links
def output_table_structures(self, verbosity = 0):
if os.path.exists(self.file_path):
if not os.path.isdir(self.file_path):
raise Exception("file_path must be a directory!")
else:
os.mkdir(self.file_path)
cat = client.CreateObject("ADOX.Catalog")
cat.ActiveConnection = self.original_con_string
linked_tables = ()
for table in cat.Tables:
if table.Type == u"TABLE":
f = open(self.file_path + os.path.sep +
"Tablestruct_" + table.Name + ".txt", "w")
conn = client.CreateObject("ADODB.Connection")
conn.ConnectionString = self.original_con_string
rs = client.CreateObject("ADODB.Recordset")
conn.Open()
rs.Open("SELECT TOP 1 * FROM [%s];" % table.Name, conn)
for field in rs.Fields:
col = table.Columns[field.Name]
col_details = (col.Name, col.Type, col.DefinedSize,
col.Attributes)
property_dict = {}
property_dict["Autoincrement"] = (
col.Properties["Autoincrement"].Value)
col_details += property_dict,
f.write(repr(col_details) + "\n")
rs.Close()
conn.Close()
f.close()
if table.Type == u"LINK":
table_details = table.Name,
table_details += table.Properties(
"Jet OLEDB:Link DataSource").Value,
table_details += table.Properties(
"Jet OLEDB:Link Provider String").Value,
table_details += table.Properties(
"Jet OLEDB:Remote Table Name").Value,
linked_tables += table_details,
if linked_tables != ():
f = open(self.file_path + os.path.sep +
"linked_list.txt", "w")
for t in linked_tables:
f.write(repr(t) + "\n")
cat.ActiveConnection.Close()
类似的反向函数使用第二个连接字符串重建数据库.
您可以使用ACE / Jet OLE DB提供程序和ADO Connection对象的OpenSchema方法来获取作为记录集的架构信息（与集合相比，它有争议，因为它可以被过滤，排序等）。
基本方法是使用adSchemaTables获取基本表（而不是VIEW），然后使用每个TABLE_NAME来获取用于ORDINAL_POSITION，！DATA_TYPE，！IS_NULLABLE，！COLUMN_HASDEFAULT，！COLUMN_DEFAULT，！CHARACTER_MAXIMUM_LENGTH，！NUMERIC_PRECISION的adSchemaColumns。
adSchemaPrimaryKeys很简单。adSchemaIndexes是您可以找到UNIQUE约束的地方，不确定是否可以将它们与唯一索引区分开，还不确定要插入adSchemaForeignKeys行集中的FOREIGN KEY的名称，例如（伪代码）：
rsFK.Filter = "FK_NAME = '" & !INDEX_NAME & "'")
-注意Jet 3.51允许基于无名PK的FK的陷阱（!!）
可以在adSchemaTableConstraints行集中找到验证规则和CHECK约束的名称，使用OpenSchema调用中的表名，然后在对adSchemaCheckConstraints行集中的调用中使用该名称，过滤CONSTRAINT_TYPE ='CHECK'（陷阱是一个名为'ValidationRule'+ Chr $（0），因此最好将名称中的空字符转义）。请记住，ACE / Jet验证规则可以是行级或表级（CHECK约束始终是表级），因此您可能需要在过滤器中使用表名：adSchemaTableConstraints为[]。[]。ValidationRule将为adSchemaCheckConstraints中的[] .ValidationRule。另一个陷阱（可疑的错误）是该字段的宽度为255个字符，因此任何超过255个字符的验证规则/检查约束定义都将具有NULL值。
adSchemaViews用于基于非参数化SELECT SQL DML的Access Query对象，非常简单；您可以在adSchemaColumns中使用VIEW名称来获取列详细信息。
PROCEDURES在adSchemaProcedures中，是Access Query对象的所有其他形式，包括参数化SELECT DML；对于后者，我更喜欢将PROCEDURE_DEFINITION中的CREATE PROCEDURE PROCEDURE_NAME替换为PARAMETERS语法。不要再看adSchemaProcedureParameters了，您什么也找不到：可以使用ADOX Catalog对象返回ADO Command来枚举参数，例如（伪代码）：
Set Command = Catalog.Procedures(PROCEDURE_NAME).Command
然后枚举.Name的Comm.Parameters集合，DATA_TYPE的.Type，IS_NULLABLE的（.Attributes和adParamNullable）枚举，COLUMN_HASDEFAULT和COLUMN_DEFAULT的.Value，.Size，.Precision和.NumericScale的。
对于ACE / Jet特定的属性（例如Unicode压缩），您需要使用另一种对象。例如，可以使用ADO Catalog对象（例如（伪代码））在访问中找到长整数自动编号：
bIsAutoincrement = Catalog.Tables(TABLE_NAME).Columns(COLUMN_NAME).Properties("Autoincrement").Value
祝好运 ：）