Create table builder structure (#659)

* Create table builder structure

* Adding comments and examples and adjusting file structure

src/ast/helpers/stmt_create_table.rs

@@ -0,0 +1,323 @@
+#[cfg(not(feature = "std"))]
+use alloc::{boxed::Box, format, string::String, vec, vec::Vec};
+
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
+
+use crate::ast::{
+    ColumnDef, FileFormat, HiveDistributionStyle, HiveFormat, ObjectName, OnCommit, Query,
+    SqlOption, Statement, TableConstraint,
+};
+use crate::parser::ParserError;
+
+/// Builder for create table statement variant ([1]).
+///
+/// This structure helps building and accessing a create table with more ease, without needing to:
+/// - Match the enum itself a lot of times; or
+/// - Moving a lot of variables around the code.
+///
+/// # Example
+/// ```rust
+/// use sqlparser::ast::helpers::stmt_create_table::CreateTableBuilder;
+/// use sqlparser::ast::{ColumnDef, DataType, Ident, ObjectName};
+/// let builder = CreateTableBuilder::new(ObjectName(vec![Ident::new("table_name")]))
+///    .if_not_exists(true)
+///    .columns(vec![ColumnDef {
+///        name: Ident::new("c1"),
+///        data_type: DataType::Int(None),
+///        collation: None,
+///        options: vec![],
+/// }]);
+/// // You can access internal elements with ease
+/// assert!(builder.if_not_exists);
+/// // Convert to a statement
+/// assert_eq!(
+///    builder.build().to_string(),
+///    "CREATE TABLE IF NOT EXISTS table_name (c1 INT)"
+/// )
+/// ```
+///
+/// [1]: crate::ast::Statement::CreateTable
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+pub struct CreateTableBuilder {
+    pub or_replace: bool,
+    pub temporary: bool,
+    pub external: bool,
+    pub global: Option<bool>,
+    pub if_not_exists: bool,
+    pub name: ObjectName,
+    pub columns: Vec<ColumnDef>,
+    pub constraints: Vec<TableConstraint>,
+    pub hive_distribution: HiveDistributionStyle,
+    pub hive_formats: Option<HiveFormat>,
+    pub table_properties: Vec<SqlOption>,
+    pub with_options: Vec<SqlOption>,
+    pub file_format: Option<FileFormat>,
+    pub location: Option<String>,
+    pub query: Option<Box<Query>>,
+    pub without_rowid: bool,
+    pub like: Option<ObjectName>,
+    pub clone: Option<ObjectName>,
+    pub engine: Option<String>,
+    pub default_charset: Option<String>,
+    pub collation: Option<String>,
+    pub on_commit: Option<OnCommit>,
+    pub on_cluster: Option<String>,
+}
+
+impl CreateTableBuilder {
+    pub fn new(name: ObjectName) -> Self {
+        Self {
+            or_replace: false,
+            temporary: false,
+            external: false,
+            global: None,
+            if_not_exists: false,
+            name,
+            columns: vec![],
+            constraints: vec![],
+            hive_distribution: HiveDistributionStyle::NONE,
+            hive_formats: None,
+            table_properties: vec![],
+            with_options: vec![],
+            file_format: None,
+            location: None,
+            query: None,
+            without_rowid: false,
+            like: None,
+            clone: None,
+            engine: None,
+            default_charset: None,
+            collation: None,
+            on_commit: None,
+            on_cluster: None,
+        }
+    }
+    pub fn or_replace(mut self, or_replace: bool) -> Self {
+        self.or_replace = or_replace;
+        self
+    }
+
+    pub fn temporary(mut self, temporary: bool) -> Self {
+        self.temporary = temporary;
+        self
+    }
+
+    pub fn external(mut self, external: bool) -> Self {
+        self.external = external;
+        self
+    }
+
+    pub fn global(mut self, global: Option<bool>) -> Self {
+        self.global = global;
+        self
+    }
+
+    pub fn if_not_exists(mut self, if_not_exists: bool) -> Self {
+        self.if_not_exists = if_not_exists;
+        self
+    }
+
+    pub fn columns(mut self, columns: Vec<ColumnDef>) -> Self {
+        self.columns = columns;
+        self
+    }
+
+    pub fn constraints(mut self, constraints: Vec<TableConstraint>) -> Self {
+        self.constraints = constraints;
+        self
+    }
+
+    pub fn hive_distribution(mut self, hive_distribution: HiveDistributionStyle) -> Self {
+        self.hive_distribution = hive_distribution;
+        self
+    }
+
+    pub fn hive_formats(mut self, hive_formats: Option<HiveFormat>) -> Self {
+        self.hive_formats = hive_formats;
+        self
+    }
+
+    pub fn table_properties(mut self, table_properties: Vec<SqlOption>) -> Self {
+        self.table_properties = table_properties;
+        self
+    }
+
+    pub fn with_options(mut self, with_options: Vec<SqlOption>) -> Self {
+        self.with_options = with_options;
+        self
+    }
+    pub fn file_format(mut self, file_format: Option<FileFormat>) -> Self {
+        self.file_format = file_format;
+        self
+    }
+    pub fn location(mut self, location: Option<String>) -> Self {
+        self.location = location;
+        self
+    }
+
+    pub fn query(mut self, query: Option<Box<Query>>) -> Self {
+        self.query = query;
+        self
+    }
+    pub fn without_rowid(mut self, without_rowid: bool) -> Self {
+        self.without_rowid = without_rowid;
+        self
+    }
+
+    pub fn like(mut self, like: Option<ObjectName>) -> Self {
+        self.like = like;
+        self
+    }
+
+    // Different name to allow the object to be cloned
+    pub fn clone_clause(mut self, clone: Option<ObjectName>) -> Self {
+        self.clone = clone;
+        self
+    }
+
+    pub fn engine(mut self, engine: Option<String>) -> Self {
+        self.engine = engine;
+        self
+    }
+
+    pub fn default_charset(mut self, default_charset: Option<String>) -> Self {
+        self.default_charset = default_charset;
+        self
+    }
+
+    pub fn collation(mut self, collation: Option<String>) -> Self {
+        self.collation = collation;
+        self
+    }
+
+    pub fn on_commit(mut self, on_commit: Option<OnCommit>) -> Self {
+        self.on_commit = on_commit;
+        self
+    }
+
+    pub fn on_cluster(mut self, on_cluster: Option<String>) -> Self {
+        self.on_cluster = on_cluster;
+        self
+    }
+
+    pub fn build(self) -> Statement {
+        Statement::CreateTable {
+            or_replace: self.or_replace,
+            temporary: self.temporary,
+            external: self.external,
+            global: self.global,
+            if_not_exists: self.if_not_exists,
+            name: self.name,
+            columns: self.columns,
+            constraints: self.constraints,
+            hive_distribution: self.hive_distribution,
+            hive_formats: self.hive_formats,
+            table_properties: self.table_properties,
+            with_options: self.with_options,
+            file_format: self.file_format,
+            location: self.location,
+            query: self.query,
+            without_rowid: self.without_rowid,
+            like: self.like,
+            clone: self.clone,
+            engine: self.engine,
+            default_charset: self.default_charset,
+            collation: self.collation,
+            on_commit: self.on_commit,
+            on_cluster: self.on_cluster,
+        }
+    }
+}
+
+impl TryFrom<Statement> for CreateTableBuilder {
+    type Error = ParserError;
+
+    // As the builder can be transformed back to a statement, it shouldn't be a problem to take the
+    // ownership.
+    fn try_from(stmt: Statement) -> Result<Self, Self::Error> {
+        match stmt {
+            Statement::CreateTable {
+                or_replace,
+                temporary,
+                external,
+                global,
+                if_not_exists,
+                name,
+                columns,
+                constraints,
+                hive_distribution,
+                hive_formats,
+                table_properties,
+                with_options,
+                file_format,
+                location,
+                query,
+                without_rowid,
+                like,
+                clone,
+                engine,
+                default_charset,
+                collation,
+                on_commit,
+                on_cluster,
+            } => Ok(Self {
+                or_replace,
+                temporary,
+                external,
+                global,
+                if_not_exists,
+                name,
+                columns,
+                constraints,
+                hive_distribution,
+                hive_formats,
+                table_properties,
+                with_options,
+                file_format,
+                location,
+                query,
+                without_rowid,
+                like,
+                clone,
+                engine,
+                default_charset,
+                collation,
+                on_commit,
+                on_cluster,
+            }),
+            _ => Err(ParserError::ParserError(format!(
+                "Expected create table statement, but received: {stmt}"
+            ))),
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::ast::helpers::stmt_create_table::CreateTableBuilder;
+    use crate::ast::{Ident, ObjectName, Statement};
+    use crate::parser::ParserError;
+
+    #[test]
+    pub fn test_from_valid_statement() {
+        let builder = CreateTableBuilder::new(ObjectName(vec![Ident::new("table_name")]));
+
+        let stmt = builder.clone().build();
+
+        assert_eq!(builder, CreateTableBuilder::try_from(stmt).unwrap());
+    }
+
+    #[test]
+    pub fn test_from_invalid_statement() {
+        let stmt = Statement::Commit { chain: false };
+
+        assert_eq!(
+            CreateTableBuilder::try_from(stmt).unwrap_err(),
+            ParserError::ParserError(
+                "Expected create table statement, but received: COMMIT".to_owned()
+            )
+        );
+    }
+}