Struct RuleCV02

pub struct RuleCV02;

Prefer using COALESCE over IFNULL or NVL.

Anti-pattern

IFNULL or NVL are commonly used to handle NULL values in SQL queries. However, they have compatibility issues across different database systems.

SELECT ifnull(foo, 0) AS bar,
FROM baz;

SELECT nvl(foo, 0) AS bar,
FROM baz;

Best Practice

It is recommended to use COALESCE instead. COALESCE is universally supported, while IFNULL is not supported in Redshift, and NVL is not supported in BigQuery. Moreover, COALESCE offers greater flexibility, as it can accept an arbitrary number of arguments, enhancing the query’s robustness.

SELECT coalesce(foo, 0) AS bar,
FROM baz;

Trait Implementations

impl Clone for RuleCV02

fn clone(&self) -> RuleCV02

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for RuleCV02

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

Formats the value using the given formatter.

impl Default for RuleCV02

fn default() -> RuleCV02

Returns the “default value” for a type.

impl Rule for RuleCV02

fn load_from_config( &self, _config: &AHashMap<String, Value>, ) -> Result<ErasedRule, String>

fn name(&self) -> &'static str

fn description(&self) -> &'static str

fn long_description(&self) -> &'static str

fn groups(&self) -> &'static [RuleGroups]

All the groups this rule belongs to, including ‘all’ because that is a given. There should be no duplicates and ‘all’ should be the first element.

fn eval(&self, context: RuleContext<'_>) -> Vec<LintResult>

fn crawl_behaviour(&self) -> Crawler

fn lint_phase(&self) -> LintPhase

fn config_ref(&self) -> &'static str

fn force_enable(&self) -> bool

fn dialect_skip(&self) -> &'static [DialectKind]

Returns the set of dialects for which a particular rule should be skipped.

fn code(&self) -> &'static str

fn is_fix_compatible(&self) -> bool

fn crawl( &self, tables: &Tables, dialect: &Dialect, fix: bool, templated_file: &TemplatedFile, tree: ErasedSegment, config: &FluffConfig, ) -> (Vec<SQLLintError>, Vec<LintFix>)

fn process_lint_result( &self, res: LintResult, templated_file: &TemplatedFile, new_lerrs: &mut Vec<SQLLintError>, new_fixes: &mut Vec<LintFix>, )