GET FIELD PROPERTIES
GET FIELD PROPERTIES ( fieldPtr | tableNum {; fieldNum}; fieldType {; fieldLength {; indexed {; unique {; invisible}}}} )
| Parameter | Type | Description | |
|---|---|---|---|
| fieldPtr | tableNum | Pointer, Longint | → | Table number or Field pointer |
| fieldNum | Integer | → | Field number if Table number is passed |
| fieldType | Integer | ← | Type of field |
| fieldLength | Integer | ← | Length of field, if Alphanumeric |
| indexed | Boolean | ← | True = Indexed, False = Non indexed |
| unique | Boolean | ← | True = Unique, False = Non unique |
| invisible | Boolean | ← | True = Invisible, False = Visible |
Description
The GET FIELD PROPERTIES command returns information about the field specified by fieldPtr or by tableNum and fieldNum.
You either pass:
- the table and field numbers in tableNum and fieldNum, or
- a pointer to the field in fieldPtr.
After the call:
- fieldType returns the type of the field. The fieldType variable parameter can take a value provided by the following predefined constants (Field and Variable Types theme):
| Constant | Type | Value |
|---|---|---|
| Is alpha field | Integer | 0 |
| Is BLOB | Integer | 30 |
| Is Boolean | Integer | 6 |
| Is date | Integer | 4 |
| Is float | Integer | 35 |
| Is integer | Integer | 8 |
| Is integer 64 bits | Integer | 25 |
| Is longint | Integer | 9 |
| Is object | Integer | 38 |
| Is picture | Integer | 3 |
| Is real | Integer | 1 |
| Is subtable | Integer | 7 |
| Is text | Integer | 2 |
| Is time | Integer | 11 |
- The fieldLen parameter returns the length of the field, if the field is Alphanumeric (i.e., fieldType=Is alpha field). The value of fieldLen is meaningless for the other field types.
- The indexed parameter returns True is the field is indexed, and False if not. The value of indexed is meaningful only for Alphanumeric, Integer, Long Integer, Real, Date, Time, and Boolean fields.
- The unique parameter returns True if the field is set to “Unique”, else False.
- The invisible parameter returns True if the field is set to “Invisible”, else False. The Invisible attribute can be used to hide a given field in 4D standard editor (label, charts...).
Example 1
This example sets the variables vType, vLength, vIndex, vUnique and vInvisible to the properties for the third field of the first table:
GET FIELD PROPERTIES(1;3;vType;vLength;vIndex;vUnique;vInvisible)
Example 2
This example sets the variables vType, vLength, vIndex, vUnique and vInvisible to the properties for the field named [Table3]Field2:
GET FIELD PROPERTIES(->[Table3]Field2;vType;vLength;vIndex;vUnique;vInvisible)