Enum IfExists 

pub enum IfExists {
    Error,
    Append,
    Overwrite,
    Upsert(Vec<String>),
}

What to do if the destination already exists.

Variants

Error

If the destination exists, return an error.

Append

If the destination exists, try to append the new data.

Overwrite

If the destination exists, overwrite the existing data.

Upsert(Vec<String>)

If the destination exists, either update or insert using the specified columns as the key. The list of keys must be non-empty, but we currently only enforce that when parsing in FromStr.

Trait Implementations

impl Clone for IfExists

fn clone(&self) -> IfExists

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for IfExists

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for IfExists

fn default() -> Self

Returns the “default value” for a type.

impl Display for IfExists

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl FromStr for IfExists

type Err = Error

The associated error which can be returned from parsing.

fn from_str(s: &str) -> Result<IfExists>

Parses a string s to return a value of this type.

impl PartialEq for IfExists

fn eq(&self, other: &IfExists) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Eq for IfExists

impl StructuralPartialEq for IfExists