Struct Settings 

pub struct Settings {
    pub format: Format,
    pub header: bool,
    pub separator: String,
    pub newline: String,
    pub nullvalue: String,
    pub table: String,
}

Everything about how output is printed, which is what the dot commands change.

Fields

format: Format

The output mode.

header: bool

Whether to print the column names.

separator: String

What goes between two values in the separated modes.

newline: String

What goes between two rows in the separated modes.

nullvalue: String

What a null prints as in the modes that do not have a spelling of their own for it.

table: String

The table name .mode insert puts in the statements it writes.

Implementations

impl Settings

pub fn set_format(&mut self, format: Format)

Switches mode, resetting both separators to that mode’s defaults.

Resetting is DuckDB’s behaviour and it surprises people, so it is worth saying why it is right: .mode csv means “write me a CSV”, and a pipe separator left over from an earlier .mode list would produce a file that is not one. The header setting is deliberately left alone, which is also DuckDB’s behaviour and was checked against the binary rather than guessed, because .headers off is a thing somebody says once and expects to stay said.

pub fn set_format_flag(&mut self, format: Format)

Switches mode the way a command line flag does, which is not the way .mode does.

There is no rule here, only a table, and the table is upstream’s. -ascii sets both separators, -csv sets the column separator and leaves the row separator, and the other ten flags set neither. That is three behaviours across three flags on one build, which is why this is a match rather than a line of code.

It matters because these are the modes people pipe into other programs. duckdb -csv ends a row with \n and duckdb -cmd ".mode csv" ends it with \r\n, and duckdb -quote writes 'a'|'b' where duckdb -cmd ".mode quote" writes 'a','b'. A script written against the flag is a script whose next stage counts bytes or splits on a character, so copying the oversight is the whole point.

Read out of .show on duckdb v2.0.0-dev84237 for all twelve flags, once on its own and once after -separator ';' -newline '@' so that leaving a separator alone can be told apart from setting it to the same thing it already was. Per #239.

Trait Implementations

impl Clone for Settings

fn clone(&self) -> Settings

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Settings

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

Formats the value using the given formatter.

impl Default for Settings

fn default() -> Self

Returns the “default value” for a type.

impl Eq for Settings

impl PartialEq for Settings

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Settings