Struct ResultSetMetadata 

#[non_exhaustive]
pub struct ResultSetMetadata {
    pub row_type: Option<StructType>,
    pub transaction: Option<Transaction>,
    pub undeclared_parameters: Option<StructType>,
    /* private fields */
}

Metadata about a ResultSet or PartialResultSet.

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

row_type: Option<StructType>

Indicates the field names and types for the rows in the result set. For example, a SQL query like "SELECT UserId, UserName FROM Users" could return a row_type value like:

"fields": [
  { "name": "UserId", "type": { "code": "INT64" } },
  { "name": "UserName", "type": { "code": "STRING" } },
]

transaction: Option<Transaction>

If the read or SQL query began a transaction as a side-effect, the information about the new transaction is yielded here.

undeclared_parameters: Option<StructType>

A SQL query can be parameterized. In PLAN mode, these parameters can be undeclared. This indicates the field names and types for those undeclared parameters in the SQL query. For example, a SQL query like "SELECT * FROM Users where UserId = @userId and UserName = @userName " could return a undeclared_parameters value like:

"fields": [
  { "name": "UserId", "type": { "code": "INT64" } },
  { "name": "UserName", "type": { "code": "STRING" } },
]

Implementations

impl ResultSetMetadata

pub fn new() -> Self

Creates a new default instance.

pub fn set_row_type<T>(self, v: T) -> Self

where T: Into<StructType>,

Sets the value of row_type.

pub fn set_or_clear_row_type<T>(self, v: Option<T>) -> Self

where T: Into<StructType>,

Sets or clears the value of row_type.

pub fn set_transaction<T>(self, v: T) -> Self

where T: Into<Transaction>,

Sets the value of transaction.

pub fn set_or_clear_transaction<T>(self, v: Option<T>) -> Self

where T: Into<Transaction>,

Sets or clears the value of transaction.

pub fn set_undeclared_parameters<T>(self, v: T) -> Self

where T: Into<StructType>,

Sets the value of undeclared_parameters.

pub fn set_or_clear_undeclared_parameters<T>(self, v: Option<T>) -> Self

where T: Into<StructType>,

Sets or clears the value of undeclared_parameters.

Trait Implementations

impl Clone for ResultSetMetadata

fn clone(&self) -> ResultSetMetadata

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ResultSetMetadata

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

Formats the value using the given formatter.

impl Default for ResultSetMetadata

fn default() -> ResultSetMetadata

Returns the “default value” for a type.

impl Message for ResultSetMetadata

fn typename() -> &'static str

The typename of this message.

impl PartialEq for ResultSetMetadata

fn eq(&self, other: &ResultSetMetadata) -> 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 StructuralPartialEq for ResultSetMetadata