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Type <type>db_val_t</type>
This structure represents a value in the database. Several data-types
are recognized and converted by the database API:
DB_INT - Value in the database
represents an integer number.
DB_DOUBLE - Value in the database
represents a decimal number.
DB_STRING - Value in the database
represents a string.
DB_STR - Value in the database
represents a string.
DB_DATETIME - Value in the database
represents date and time.
DB_BLOB - Value in the database
represents binary large object.
These data-types are automatically recognized, converted from internal
database representation and stored in a variable of corresponding type.
typedef struct db_val {
db_type_t type; /* Type of the value */
int nul; /* NULL flag */
union {
int int_val; /* Integer value */
double double_val; /* Double value */
time_t time_val; /* Unix time_t value */
const char* string_val; /* Zero terminated string */
str str_val; /* str structure */
str blob_val; /* Structure describing blob */
} val;
} db_val_t;
All macros expect pinter to db_val_t variable as a
parameter.
VAL_TYPE(value) Macro.
Use this macro if you need to set/get the type of the value
VAL_TYPE Macro
...
VAL_TYPE(val) = DB_INT;
if (VAL_TYPE(val) == DB_FLOAT)
...
VAL_NULL(value) Macro.
Use this macro if you need to set/get the null flag. Non-zero
flag means that the corresponding cell in the database
contained no data (NULL value in MySQL
terminology).
VAL_NULL Macro
...
if (VAL_NULL(val) == 1) {
printf("The cell is NULL");
}
...
VAL_INT(value) Macro.
Use this macro if you need to access integer value
in db_val_t structure.
VAL_INT Macro
...
if (VAL_TYPE(val) == DB_INT) {
printf("%d", VAL_INT(val));
}
...
VAL_DOUBLE(value) Macro.
Use this macro if you need to access double value
in the db_val_t structure.
VAL_DOUBLE Macro
...
if (VAL_TYPE(val) == DB_DOUBLE) {
printf("%f", VAL_DOUBLE(val));
}
...
VAL_TIME(value) Macro.
Use this macro if you need to access time_t value
in db_val_t structure.
VAL_TIME Macro
...
time_t tim;
if (VAL_TYPE(val) == DB_DATETIME) {
tim = VAL_TIME(val);
}
...
VAL_STRING(value) Macro.
Use this macro if you need to access string value
in db_val_t structure.
VAL_STRING Macro
...
if (VAL_TYPE(val) == DB_STRING) {
printf("%s", VAL_STRING(val));
}
...
VAL_STR(value) Macro.
Use this macro if you need to access str structure
in db_val_t structure.
VAL_STR Macro
...
if (VAL_TYPE(val) == DB_STR) {
printf("%.*s", VAL_STR(val).len, VAL_STR(val).s);
}
...
VAL_BLOB(value) Macro.
Use this macro if you need to access blob value in db_val_t structure.
VAL_STR Macro
...
if (VAL_TYPE(val) == DB_BLOB) {
printf("%.*s", VAL_BLOB(val).len, VAL_BLOB(val).s);
}
...