JET_INDEXLIST Structure

Artikkel
08/26/2021

Applies to: Windows | Windows Server

JET_INDEXLIST Structure

The JET_INDEXLIST structure contains the necessary information to traverse a temporary table that is created by the JetGetIndexInfo or JetGetTableIndexInfo functions. Each row in the temporary table describes a column of an index.

    typedef struct {
      unsigned long cbStruct;
      JET_TABLEID tableid;
      gned long cRecord;
      JET_COLUMNID columnidindexname;
      JET_COLUMNID columnidgrbitIndex;
      JET_COLUMNID columnidcKey;
      JET_COLUMNID columnidcEntry;
      JET_COLUMNID columnidcPage;
      JET_COLUMNID columnidcColumn;
      JET_COLUMNID columnidiColumn;
      JET_COLUMNID columnidcolumnid;
      JET_COLUMNID columnidcoltyp;
      JET_COLUMNID columnidCountry;
      JET_COLUMNID columnidLangid;
      JET_COLUMNID columnidCp;
      JET_COLUMNID columnidCollate;
      JET_COLUMNID columnidgrbitColumn;
      JET_COLUMNID columnidcolumnname;
      JET_COLUMNID columnidLCMapFlags;
    } JET_INDEXLIST;

Members

cbStruct

The size of the structure in bytes. The API call will update this field, so the caller should ensure that this value matches sizeof( JET_INDEXLIST ).

tableid

The table identifier of the temporary table that was created. It is the responsibility of the caller to close the table.

cRecord

The number of records in the temporary table that was created.

columnidindexname

The column identifier of the name of the index.

This column is a JET_coltypText.

columnidgrbitIndex

The column identifier of the grbits used on the index. See JET_INDEXCREATE for a list of valid bits.

This column is a JET_coltypLong.

columnidcKey

The column identifier of the number of keys in the index.

This column is a JET_coltypLong.

columnidcEntry

The column identifier of the number of entries in the index.

This column is a JET_coltypLong.

columnidcPage

The column identifier of the number of pages the index uses.This column is a JET_coltypLong.

columnidcColumn

The column identifier of the total number of columns that the index spans.

This column is a JET_coltypLong.

columnidiColumn

The column identifier of the number of the columns in the index. For more information, see the Remarks section of this topic.

This column is a JET_coltypLong.

Value	Meaning
cIndexInfoCols 15	Specifies that 15 columns are allowed.
cColumnInfoCols 14	Specifies that 14 columns are allowed.
cObjectInfoCols 9	Specifies that 9 columns are allowed.

columnidcolumnid

The column identifier of the column that is indexed.For more information, see the Remarks section of this topic. This column is a JET_coltypLong.

columnidcoltyp

The column identifier of the coltyp of the column which is indexed. For more information, see the Remarks section of this topic. This column is a JET_coltypLong.

columnidCountry

The column identifier of the country code of the column that is indexed. The country code is deprecated.

This column is a JET_coltypShort.

columnidLangid

The column identifier of the language identifier (LCID) under which the index was created. For more information, see JET_INDEXCREATE.

This column is a JET_coltypShort.

columnidCp

The column identifier of the code page under which the index was created. For more information, see JET_COLUMNCREATE.

This column is a JET_coltypShort.

columnidCollate

The column identifier of the collation sequence under which the index was created. The collation sequence is deprecated.

This column is a JET_coltypShort.

columnidgrbitColumn

The column identifier of the grbits that apply to the order of the column in the index.

The data for this column can be ordered as JET_bitKeyAscending or JET_bitKeyDescending. This column is a JET_coltypLong. For example, an index defined as "-column1\0+column2\0" will have JET_bitKeyDescending for "column1", and JET_bitKeyAscending for "column2".

The following options are valid for this member.

Value	Meaning
JET_bitKeyAscending	An index segment in ascending order.
JET_bitKeyDescending	An index segment in descending order.

columnidcolumnname

The column identifier of the name of the column.

This column is a JET_coltypText.

columnidLCMapFlags

The column identifier of the flags that are used to create the index. For more information, see the dwMapFlags section of JET_UNICODEINDEX.

This column is a JET_coltypLong.

Remarks

Each row in the temporary table corresponds to a column in a particular index.

For example, the index "+A\0+B\0+C\0+D\0+E\0" is more than five columns, and it will occupy five rows in the temporary table. Each of these five rows will have a value of 5 in the column that is identified by columnid column. But each row will have a different value for columnid column, ranging from 0 to 4.

The number of keys in a particular index corresponds to the number of unique values for which a caller can seek and get an exact match. The number of entries is the number of rows that an index matches. If an index has a uniqueness constraint, then the number of keys is equal to the number of entries. For example, if a table contains the following information and an index is created over the column named "key", then there are three keys (100, 200, and 500), but there are four entries ("this", "is", "an", and "example").

Key	Entry
100	"this"
100	"is"
200	"an"
500	"example"

Requirements

Requirement	Value
Client	Requires Windows Vista, Windows XP, or Windows 2000 Professional.
Server	Requires Windows Server 2008, Windows Server 2003, or Windows 2000 Server.
Header	Declared in Esent.h.

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JET_INDEXLIST Structure