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Diffstat (limited to 'user_guide_src/source/database/fields.rst')
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diff --git a/user_guide_src/source/database/fields.rst b/user_guide_src/source/database/fields.rst new file mode 100644 index 000000000..07730f5d3 --- /dev/null +++ b/user_guide_src/source/database/fields.rst @@ -0,0 +1,59 @@ +########## +Field Data +########## + +$this->db->list_fields() +========================= + +Returns an array containing the field names. This query can be called +two ways: + +1. You can supply the table name and call it from the $this->db-> +object:: + + $fields = $this->db->list_fields('table_name'); foreach ($fields as $field) { echo $field; } + +2. You can gather the field names associated with any query you run by +calling the function from your query result object:: + + $query = $this->db->query('SELECT * FROM some_table'); foreach ($query->list_fields() as $field) { echo $field; } + +$this->db->field_exists() +========================== + +Sometimes it's helpful to know whether a particular field exists before +performing an action. Returns a boolean TRUE/FALSE. Usage example:: + + if ($this->db->field_exists('field_name', 'table_name')) { // some code... } + +Note: Replace *field_name* with the name of the column you are looking +for, and replace *table_name* with the name of the table you are +looking for. + +$this->db->field_data() +======================== + +Returns an array of objects containing field information. + +Sometimes it's helpful to gather the field names or other metadata, like +the column type, max length, etc. + +Note: Not all databases provide meta-data. + +Usage example:: + + $fields = $this->db->field_data('table_name'); foreach ($fields as $field) { echo $field->name; echo $field->type; echo $field->max_length; echo $field->primary_key; } + +If you have run a query already you can use the result object instead of +supplying the table name:: + + $query = $this->db->query("YOUR QUERY"); $fields = $query->field_data(); + +The following data is available from this function if supported by your +database: + +- name - column name +- max_length - maximum length of the column +- primary_key - 1 if the column is a primary key +- type - the type of the column + |