mozIStorageValueArray 编辑

The mozIStorageValueArray interface obtains provides methods to obtain data from a given result.

For an introduction on how to use this interface, see the Storage overview document.

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Inherits from: nsISupports

Method overview

long getTypeOfIndex(in unsigned long aIndex);

long getInt32(in unsigned long aIndex);

long long getInt64(in unsigned long aIndex);

double getDouble(in unsigned long aIndex);

AUTF8String getUTF8String(in unsigned long aIndex);

AString getString(in unsigned long aIndex);

void getBlob(in unsigned long aIndex, out unsigned long aDataSize, [array,size_is(aDataSize)] out octet aData);

boolean getIsNull(in unsigned long aIndex);

Attributes

Attribute	Type	Description
numEntries	unsigned long	The number of entries in the array.

Constants

Constant	Value	Description
VALUE_TYPE_NULL	0	Null data type.
VALUE_TYPE_INTEGER	1	INTEGER data type.
VALUE_TYPE_FLOAT	2	FLOAT data type.
VALUE_TYPE_TEXT	3	TEXT data type.
VALUE_TYPE_BLOB	4	BLOB data type.

Methods

getTypeOfIndex()

Returns the type of the value at the given column index.

 long getTypeOfIndex(
   in unsigned long aIndex
 );

Parameters

aIndex

The zero-based numerical index for the column to get the data from.

Return value

One of the constants mozIStorageValueArray.VALUE_TYPE_NULL, mozIStorageValueArray.VALUE_TYPE_INTEGER, mozIStorageValueArray.VALUE_TYPE_FLOAT, mozIStorageValueArray.VALUE_TYPE_TEXT, or mozIStorageValueArray.VALUE_TYPE_BLOB describing the type aIndex is.

getInt32()

Obtains a Int32 from the specified index.

 long getInt32(
   in unsigned long aIndex
 );

Parameters

aIndex

The zero-based numerical index for the column to get the data from.

Return value

The int32 for the specified entry.

getInt64()

Obtains a int64 from the specified index.

 long long getInt64(
   in unsigned long aIndex
 );

Parameters

aIndex

The zero-based numerical index for the column to get the data from.

Return value

The int64 for the specified entry.

getDouble()

Obtains a double from the specified index.

 double getDouble(
   in unsigned long aIndex
 );

Parameters

aIndex

The zero-based numerical index for the column to get the data from.

Return value

The double for the specified entry.

getUTF8String()

Obtains a UTF8String from the specified index.

Note: C++ callers should be aware that a string value for a NULL column has IsVoid set to distinguish it from an empty string.

 AUTF8String getUTF8String(
   in unsigned long aIndex
 );

Parameters

aIndex

The zero-based numerical index for the column to get the data from.

Return value

The utf8string for the specified entry.

getString()

Obtains a string from the specified index.

Note: C++ callers should be aware that a string value for a NULL column has IsVoid set to distinguish it from an empty string.

 AString getString(
   in unsigned long aIndex
 );

Parameters

aIndex

The zero-based numerical index for the column to get the data from.

Return value

The string for the specified entry.

getBlob()

Obtains a blob from the specified index.

 void getBlob(
   in unsigned long aIndex,
   out unsigned long aDataSize,
   [array,size_is(aDataSize)] out octet aData
 );

Parameters

aIndex

The zero-based numerical index for the column to get the data from.

aDataSize

The size of the returned array.

Return value

The blob for the specified entry.

getIsNull()

Checks if given column index is NULL.

 boolean getIsNull(
   in unsigned long aIndex
 );

Parameters

aIndex

The zero-based numerical index for the column to get the data from.

Return value

Returns true if the column specified by aIndex is NULL, or false otherwise.

See also

• Storage introduction and how-to article
• mozIStorageConnection Database connection to a specific file or in-memory data storage
• mozIStorageStatement Create and execute SQL statements on a SQLite database.
• mozIStorageFunction Create a new SQLite function.
• mozIStorageAggregateFunction Create a new SQLite aggregate function.
• mozIStorageProgressHandler Monitor progress during the execution of a statement.
• mozIStorageStatementWrapper Storage statement wrapper