diff --git a/crates/squawk_ide/src/code_actions/add_explicit_alias.rs b/crates/squawk_ide/src/code_actions/add_explicit_alias.rs
index b32cb26d..c06cacdc 100644
--- a/crates/squawk_ide/src/code_actions/add_explicit_alias.rs
+++ b/crates/squawk_ide/src/code_actions/add_explicit_alias.rs
@@ -4,7 +4,8 @@ use squawk_linter::Edit;
 use squawk_syntax::ast::{self, AstNode};
 use squawk_syntax::quote::quote_column_alias;
 
-use crate::{column_name::ColumnName, file::InFile, offsets::token_from_offset};
+use crate::{file::InFile, offsets::token_from_offset};
+use squawk_syntax::column_name::ColumnName;
 
 use super::{ActionKind, CodeAction};
 
diff --git a/crates/squawk_ide/src/code_actions/remove_redundant_alias.rs b/crates/squawk_ide/src/code_actions/remove_redundant_alias.rs
index 48810ffa..bc848572 100644
--- a/crates/squawk_ide/src/code_actions/remove_redundant_alias.rs
+++ b/crates/squawk_ide/src/code_actions/remove_redundant_alias.rs
@@ -3,7 +3,8 @@ use salsa::Database as Db;
 use squawk_linter::Edit;
 use squawk_syntax::ast::{self, AstNode};
 
-use crate::{column_name::ColumnName, file::InFile, offsets::token_from_offset, symbols::Name};
+use crate::{file::InFile, offsets::token_from_offset, symbols::Name};
+use squawk_syntax::column_name::ColumnName;
 
 use super::{ActionKind, CodeAction};
 
diff --git a/crates/squawk_ide/src/collect.rs b/crates/squawk_ide/src/collect.rs
index 7aadc80a..76b531b6 100644
--- a/crates/squawk_ide/src/collect.rs
+++ b/crates/squawk_ide/src/collect.rs
@@ -1,5 +1,4 @@
 use crate::ast_nav;
-use crate::column_name::ColumnName;
 use crate::db::{File, bind, list_files, parse};
 use crate::file::InFile;
 use crate::goto_definition::goto_definition;
@@ -11,6 +10,7 @@ use crate::resolve::{
     resolve_table_like, resolve_table_name, table_ptr_from_from_item,
 };
 use salsa::Database as Db;
+use squawk_syntax::column_name::ColumnName;
 use squawk_syntax::{
     SyntaxNode, SyntaxNodePtr,
     ast::{self, AstNode},
diff --git a/crates/squawk_ide/src/hover.rs b/crates/squawk_ide/src/hover.rs
index 1b2bfb10..fd06c543 100644
--- a/crates/squawk_ide/src/hover.rs
+++ b/crates/squawk_ide/src/hover.rs
@@ -1,6 +1,5 @@
 use crate::ast_nav;
 use crate::collect;
-use crate::column_name::ColumnName;
 use crate::comments::preceding_comment;
 use crate::db::{File, bind, list_files, parse};
 use crate::file::InFile;
@@ -19,6 +18,7 @@ use squawk_line_index::find_newline;
 use squawk_syntax::SyntaxNode;
 use squawk_syntax::SyntaxNodePtr;
 use squawk_syntax::ast::LitKind;
+use squawk_syntax::column_name::ColumnName;
 use squawk_syntax::{
     SyntaxKind,
     ast::{self, AstNode},
diff --git a/crates/squawk_ide/src/lib.rs b/crates/squawk_ide/src/lib.rs
index 94e459b8..eb01b571 100644
--- a/crates/squawk_ide/src/lib.rs
+++ b/crates/squawk_ide/src/lib.rs
@@ -4,7 +4,6 @@ pub mod builtins;
 mod classify;
 pub mod code_actions;
 mod collect;
-pub mod column_name;
 mod comments;
 pub mod completion;
 pub mod db;
diff --git a/crates/squawk_ide/src/resolve.rs b/crates/squawk_ide/src/resolve.rs
index 253efa98..6583c791 100644
--- a/crates/squawk_ide/src/resolve.rs
+++ b/crates/squawk_ide/src/resolve.rs
@@ -7,7 +7,6 @@ use squawk_syntax::{
 };
 
 use crate::binder::ResolvedSchemas;
-use crate::column_name::ColumnName;
 use crate::db::File;
 use crate::file::InFile;
 use crate::location::{Location, LocationKind};
@@ -19,6 +18,7 @@ use crate::{
     db::{bind, parse},
 };
 use salsa::Database as Db;
+use squawk_syntax::column_name::ColumnName;
 
 fn resolve_named_arg_parameter<T>(
     db: &dyn Db,
diff --git a/crates/squawk_linter/src/rules/ban_duplicate_column_assignments.rs b/crates/squawk_linter/src/rules/ban_duplicate_column_assignments.rs
index c8814d1b..98158a4f 100644
--- a/crates/squawk_linter/src/rules/ban_duplicate_column_assignments.rs
+++ b/crates/squawk_linter/src/rules/ban_duplicate_column_assignments.rs
@@ -1,7 +1,8 @@
 use rustc_hash::FxHashMap;
 use squawk_syntax::{
-    Parse, SourceFile, SyntaxKind,
+    Parse, SourceFile, SyntaxKind, SyntaxNode,
     ast::{self, AstNode, NameLike},
+    column_name::ColumnName,
 };
 
 use rowan::TextRange;
@@ -15,7 +16,10 @@ struct Name(String);
 
 impl Name {
     fn from_node(node: &impl NameLike) -> Self {
-        let mut text = node.text();
+        Self::from_string(node.text())
+    }
+
+    fn from_string(mut text: String) -> Self {
         text.truncate(text.floor_char_boundary(MAX_IDENT_BYTES));
         Self(text)
     }
@@ -46,10 +50,81 @@ pub(crate) fn ban_duplicate_column_assignments(ctx: &mut Linter, parse: &Parse<S
             && let Some(column_target_list) = insert.column_target_list()
         {
             check_insert_column_target_list(ctx, &column_target_list);
-        } else if let Some(merge_insert) = ast::MergeInsert::cast(node)
+        } else if let Some(merge_insert) = ast::MergeInsert::cast(node.clone())
             && let Some(column_target_list) = merge_insert.column_target_list()
         {
             check_insert_column_target_list(ctx, &column_target_list);
+        } else if let Some(create_table) = ast::CreateTableLike::cast(node.clone())
+            && let Some(table_arg_list) = create_table.table_arg_list()
+        {
+            check_table_arg_list(ctx, &table_arg_list);
+        } else if let Some(create_table_as) = ast::CreateTableAs::cast(node.clone())
+            && let Some(table_arg_list) = create_table_as.table_arg_list()
+        {
+            check_table_arg_list(ctx, &table_arg_list);
+        } else if let Some(create_view) = ast::CreateViewLike::cast(node.clone()) {
+            if let Some(column_list) = create_view.column_list() {
+                check_defined_columns(ctx, column_list.column_names());
+            } else if let Some(target_list) =
+                create_view.query().and_then(|query| query.target_list())
+            {
+                check_target_aliases(ctx, &target_list);
+            }
+        } else if let Some(select_into) = ast::SelectInto::cast(node)
+            && let Some(target_list) = select_into
+                .select_clause()
+                .and_then(|select_clause| select_clause.target_list())
+        {
+            check_target_aliases(ctx, &target_list);
+        }
+    }
+}
+
+fn check_table_arg_list(ctx: &mut Linter, table_arg_list: &ast::TableArgList) {
+    check_defined_columns(
+        ctx,
+        table_arg_list.args().filter_map(|arg| match arg {
+            ast::TableArg::Column(column) => column.name(),
+            _ => None,
+        }),
+    );
+}
+
+fn check_target_aliases(ctx: &mut Linter, target_list: &ast::TargetList) {
+    check_defined_nodes(
+        ctx,
+        target_list.targets().filter_map(|target| {
+            let (name, node) = ColumnName::from_target(target)?;
+            Some((Name::from_string(name.to_string()?), node))
+        }),
+    );
+}
+
+fn check_defined_columns(ctx: &mut Linter, columns: impl Iterator<Item = ast::ColumnName>) {
+    check_defined_nodes(
+        ctx,
+        columns.map(|column| (Name::from_node(&column), column.syntax().clone())),
+    );
+}
+
+fn check_defined_nodes(ctx: &mut Linter, columns: impl Iterator<Item = (Name, SyntaxNode)>) {
+    let mut defined_columns: FxHashMap<Name, Vec<SyntaxNode>> = FxHashMap::default();
+
+    for (name, column) in columns {
+        defined_columns.entry(name).or_default().push(column);
+    }
+
+    for (name, columns) in defined_columns {
+        if columns.len() < 2 {
+            continue;
+        }
+
+        for column in columns {
+            ctx.report(Violation::for_node(
+                Rule::BanDuplicateColumnAssignments,
+                format!("Column `{}` is specified more than once.", name.as_str()),
+                &column,
+            ));
         }
     }
 }
@@ -430,6 +505,115 @@ when not matched then
         ");
     }
 
+    #[test]
+    fn create_table_err() {
+        let sql = r#"
+create table t (
+  a int,
+  a text
+);
+"#;
+        assert_snapshot!(lint(sql), @"
+        warning[ban-duplicate-column-assignments]: Column `a` is specified more than once.
+          ╭▸ 
+        3 │   a int,
+          ╰╴  ━
+        warning[ban-duplicate-column-assignments]: Column `a` is specified more than once.
+          ╭▸ 
+        4 │   a text
+          ╰╴  ━
+        ");
+    }
+
+    #[test]
+    fn create_foreign_table_err() {
+        let sql = r#"
+create foreign table t (
+  a int,
+  a text
+) server s;
+"#;
+        assert_snapshot!(lint(sql), @"
+        warning[ban-duplicate-column-assignments]: Column `a` is specified more than once.
+          ╭▸ 
+        3 │   a int,
+          ╰╴  ━
+        warning[ban-duplicate-column-assignments]: Column `a` is specified more than once.
+          ╭▸ 
+        4 │   a text
+          ╰╴  ━
+        ");
+    }
+
+    #[test]
+    fn create_view_err() {
+        let sql = r#"
+create view v (a, a) as
+select 1, 2;
+"#;
+        assert_snapshot!(lint(sql), @"
+        warning[ban-duplicate-column-assignments]: Column `a` is specified more than once.
+          ╭▸ 
+        2 │ create view v (a, a) as
+          ╰╴               ━
+        warning[ban-duplicate-column-assignments]: Column `a` is specified more than once.
+          ╭▸ 
+        2 │ create view v (a, a) as
+          ╰╴                  ━
+        ");
+    }
+
+    #[test]
+    fn create_view_with_duplicate_target_aliases_err() {
+        let sql = r#"
+create view v as
+select 1 a, 2 a;
+"#;
+        assert_snapshot!(lint(sql), @"
+        warning[ban-duplicate-column-assignments]: Column `a` is specified more than once.
+          ╭▸ 
+        3 │ select 1 a, 2 a;
+          ╰╴         ━
+        warning[ban-duplicate-column-assignments]: Column `a` is specified more than once.
+          ╭▸ 
+        3 │ select 1 a, 2 a;
+          ╰╴              ━
+        ");
+    }
+
+    #[test]
+    fn create_view_with_duplicate_inferred_names_err() {
+        let sql = r#"
+create view v as
+select 1, 2;
+"#;
+        assert_snapshot!(lint(sql), @"
+        warning[ban-duplicate-column-assignments]: Column `?column?` is specified more than once.
+          ╭▸ 
+        3 │ select 1, 2;
+          ╰╴       ━
+        warning[ban-duplicate-column-assignments]: Column `?column?` is specified more than once.
+          ╭▸ 
+        3 │ select 1, 2;
+          ╰╴          ━
+        ");
+    }
+
+    #[test]
+    fn select_into_err() {
+        let sql = "select 1 a, 2 a into z;";
+        assert_snapshot!(lint(sql), @"
+        warning[ban-duplicate-column-assignments]: Column `a` is specified more than once.
+          ╭▸ 
+        1 │ select 1 a, 2 a into z;
+          ╰╴         ━
+        warning[ban-duplicate-column-assignments]: Column `a` is specified more than once.
+          ╭▸ 
+        1 │ select 1 a, 2 a into z;
+          ╰╴              ━
+        ");
+    }
+
     #[test]
     fn conflict_update_err() {
         let sql = r#"
@@ -503,6 +687,19 @@ set
   A = 2;
 insert into k (a, b)
 values (1, 2);
+create table t (
+  a int,
+  b int
+);
+create foreign table ft (
+  a int,
+  b int
+) server s;
+create view v (a, b) as
+select 1 a, 2 a;
+create view inferred_v as
+select 1 a, 2 b;
+select 1 a, 2 b into z;
 insert into k (a.x, a.y)
 values (1, 2);
 merge into k
diff --git a/crates/squawk_ide/src/column_name.rs b/crates/squawk_syntax/src/column_name.rs
similarity index 98%
rename from crates/squawk_ide/src/column_name.rs
rename to crates/squawk_syntax/src/column_name.rs
index eb17bf12..b6a3bc9d 100644
--- a/crates/squawk_ide/src/column_name.rs
+++ b/crates/squawk_syntax/src/column_name.rs
@@ -1,10 +1,10 @@
-use squawk_syntax::{
+use crate::{
     SyntaxKind, SyntaxNode,
     ast::{self, AstNode},
 };
 
 #[derive(Clone, Debug, PartialEq)]
-pub(crate) enum ColumnName {
+pub enum ColumnName {
     Column(String),
     /// There's a fallback mechanism that we need to propagate through the
     /// expressions/types.
@@ -23,7 +23,7 @@ pub(crate) enum ColumnName {
 
 impl ColumnName {
     // Get the alias, otherwise infer the column name.
-    pub(crate) fn from_target(target: ast::Target) -> Option<(ColumnName, SyntaxNode)> {
+    pub fn from_target(target: ast::Target) -> Option<(ColumnName, SyntaxNode)> {
         if let Some(as_name) = target.as_name()
             && let Some(name_node) = as_name.name()
         {
@@ -36,7 +36,7 @@ impl ColumnName {
     }
 
     // Ignore any aliases, just infer the what the column name.
-    pub(crate) fn inferred_from_target(target: ast::Target) -> Option<(ColumnName, SyntaxNode)> {
+    pub fn inferred_from_target(target: ast::Target) -> Option<(ColumnName, SyntaxNode)> {
         if let Some(expr) = target.expr()
             && let Some(name) = name_from_expr(expr, false)
         {
@@ -55,7 +55,7 @@ impl ColumnName {
         }
     }
 
-    pub(crate) fn to_string(&self) -> Option<String> {
+    pub fn to_string(&self) -> Option<String> {
         match self {
             ColumnName::Column(string) => Some(string.to_string()),
             ColumnName::Star => None,
@@ -695,7 +695,7 @@ fn examples() {
     #[track_caller]
     fn name(sql: &str) -> String {
         let sql = "select ".to_string() + sql;
-        let parse = squawk_syntax::SourceFile::parse(&sql);
+        let parse = crate::SourceFile::parse(&sql);
         assert_eq!(parse.errors(), vec![]);
         let file = parse.tree();
 
diff --git a/crates/squawk_syntax/src/lib.rs b/crates/squawk_syntax/src/lib.rs
index 1b40cc43..cc94590f 100644
--- a/crates/squawk_syntax/src/lib.rs
+++ b/crates/squawk_syntax/src/lib.rs
@@ -25,6 +25,7 @@
 // DEALINGS IN THE SOFTWARE.
 
 pub mod ast;
+pub mod column_name;
 mod generated;
 mod parsing;
 mod ptr;
diff --git a/docs/docs/ban-duplicate-column-assignments.md b/docs/docs/ban-duplicate-column-assignments.md
index b18c33be..bb393ce5 100644
--- a/docs/docs/ban-duplicate-column-assignments.md
+++ b/docs/docs/ban-duplicate-column-assignments.md
@@ -5,23 +5,21 @@ title: ban-duplicate-column-assignments
 
 ## problem
 
-Assigning to a column more than once in Postgres results in a runtime error.
+Assigning/declaring a column more than once results in a runtime error in
+Postgres.
 
 ```sql
-create table t(a int);
+create table t(a int, a text);
+create view v (a, a) as select 1, 2;
 update t set a = 1, a = 2;
 ```
 
-gives:
-
-```
-Query 1 ERROR at Line 1: : ERROR:  multiple assignments to same column "a"
-```
-
 ## solution
 
-Remove your dupe assignment:
+Remove duplicate assignments/declarations:
 
 ```sql
+create table t(a int);
+create view v (a, b) as select 1, 2;
 update t set a = 2;
 ```