harmony 鸿蒙oh_data_value.h

2025-06-12
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oh_data_value.h

Overview

Defines APIs and enums related to a single data value.

Since API version 18, OH_ColumnType is moved from oh_cursor.h to this file. This type is supported in versions earlier than API version 18 and can be used in all versions.

File to include: <database/data/oh_data_value.h>

Library: libnative_rdb_ndk.z.so

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Since: 18

Related module: RDB

Summary

Types

Name	Description
typedef enum OH_ColumnType OH_ColumnType	Defines an enum for column types.
typedef struct OH_Data_Value OH_Data_Value	Defines the OH_Data_Value struct.

Enums

Name	Description
OH_ColumnType { TYPE_NULL = 0, TYPE_INT64, TYPE_REAL, TYPE_TEXT, TYPE_BLOB, TYPE_ASSET, TYPE_ASSETS, TYPE_FLOAT_VECTOR, TYPE_UNLIMITED_INT }	Enumerates the column types.

Functions

Name	Description
OH_Data_Value * OH_Value_Create (void)	Creates an OH_Data_Value instance to store a single KV pair.
int OH_Value_Destroy (OH_Data_Value *value)	Destroys an OH_Data_Value instance.
int OH_Value_PutNull (OH_Data_Value *value)	Adds empty data.
int OH_Value_PutInt (OH_Data_Value *value, int64_t val)	Adds integer data.
int OH_Value_PutReal (OH_Data_Value *value, double val)	Adds data of the REAL type.
int OH_Value_PutText (OH_Data_Value value, const char val)	Adds data of the string type.
int OH_Value_PutBlob (OH_Data_Value value, const unsigned char val, size_t length)	Adds data of the BLOB type.
int OH_Value_PutAsset (OH_Data_Value value, const Data_Asset val)	Adds data of the ASSET type.
int OH_Value_PutAssets (OH_Data_Value value, const Data_Asset const *val, size_t length)	Adds data of the ASSETS type.
int OH_Value_PutFloatVector (OH_Data_Value value, const float val, size_t length)	Adds data of the floating-point array type.
int OH_Value_PutUnlimitedInt (OH_Data_Value value, int sign, const uint64_t trueForm, size_t length)	Adds an integer array of any length.
int OH_Value_GetType (OH_Data_Value value, OH_ColumnType type)	Obtains the data type.
int OH_Value_IsNull (OH_Data_Value value, bool val)	Checks whether a value is null.
int OH_Value_GetInt (OH_Data_Value value, int64_t val)	Obtains integer data.
int OH_Value_GetReal (OH_Data_Value value, double val)	Obtains data of the REAL type.
int OH_Value_GetText (OH_Data_Value value, const char *val)	Obtains data of the string type.
int OH_Value_GetBlob (OH_Data_Value value, const uint8_t val, size_t length)	Obtains data of the BLOB type.
int OH_Value_GetAsset (OH_Data_Value value, Data_Asset val)	Obtains data of the ASSET type.
int OH_Value_GetAssetsCount (OH_Data_Value value, size_t length)	Obtains the length of ASSETS data.
int OH_Value_GetAssets (OH_Data_Value value, Data_Asset val, size_t inLen, size_t outLen)	Obtains data of the ASSETS type.
int OH_Value_GetFloatVectorCount (OH_Data_Value value, size_t length)	Obtains the length of a floating-point array.
int OH_Value_GetFloatVector (OH_Data_Value value, float val, size_t inLen, size_t *outLen)	Obtains data of the floating-point array type.
int OH_Value_GetUnlimitedIntBand (OH_Data_Value value, size_t length)	Obtains the length of an integer of any length.
int OH_Value_GetUnlimitedInt (OH_Data_Value value, int sign, uint64_t trueForm, size_t inLen, size_t outLen)	Obtains integer data of any length.