From b32d4dd98f9a0dcbf986d1980f74ab18171bf639 Mon Sep 17 00:00:00 2001
From: Martijn Visser <mgvisser@gmail.com>
Date: Fri, 24 Apr 2026 14:03:25 +0200
Subject: [PATCH] Change juliatype for DATETIME and TIMESTAMP to String

---
 src/SQLite.jl    |  6 ++----
 test/runtests.jl | 41 ++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 42 insertions(+), 5 deletions(-)

diff --git a/src/SQLite.jl b/src/SQLite.jl
index d8f2927..93cd58b 100644
--- a/src/SQLite.jl
+++ b/src/SQLite.jl
@@ -527,10 +527,8 @@ function juliatype(decl_typestr::AbstractString, default::Type = Any)
         return String
     elseif typeuc == "BLOB"
         return Any
-    elseif typeuc == "DATETIME"
-        return default # FIXME
-    elseif typeuc == "TIMESTAMP"
-        return default # FIXME
+    elseif typeuc in ("DATETIME", "TIMESTAMP")
+        return String
     elseif occursin(
         r"^N?V?A?R?Y?I?N?G?\s*CHARA?C?T?E?R?T?E?X?T?\s*\(?\d*\)?$"i,
         typeuc,
diff --git a/test/runtests.jl b/test/runtests.jl
index 912d4d4..209d913 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -843,7 +843,7 @@ end
         tbl1 = (a = [1, 2, 3], b = [4, 5, 6])
         SQLite.load!(tbl1, db, "data_default")
         SQLite.load!(tbl1, db, "data_strict", strict=true)
-        
+
         tbl2 = (a = ["a", "b", "c"], b=[7, 8, 9])
         SQLite.load!(tbl2, db, "data_default")
         @test_throws SQLiteException SQLite.load!(tbl2, db, "data_strict")
@@ -1161,4 +1161,43 @@ end
         db_b,
         "select myfunc(1) as x",
     )
+
+    # DATETIME and TIMESTAMP declared types should map to String
+    @testset "DATETIME/TIMESTAMP juliatype" begin
+        # juliatype should return String regardless of the default
+        @test SQLite.juliatype("DATETIME") == String
+        @test SQLite.juliatype("TIMESTAMP") == String
+        @test SQLite.juliatype("DATETIME", Missing) == String
+        @test SQLite.juliatype("TIMESTAMP", Missing) == String
+        @test SQLite.juliatype("datetime") == String
+        @test SQLite.juliatype("timestamp") == String
+    end
+
+    @testset "DATETIME/TIMESTAMP strict mode with NULL" begin
+        db = SQLite.DB()
+        DBInterface.execute(db, "CREATE TABLE dt_test (id INTEGER, ts TIMESTAMP)")
+        # Insert NULL first, then a non-NULL value
+        DBInterface.execute(db, "INSERT INTO dt_test VALUES (1, NULL)")
+        DBInterface.execute(db, "INSERT INTO dt_test VALUES (2, '2024-01-01 00:00:00')")
+
+        # strict mode
+        tbl = DBInterface.execute(
+            DBInterface.prepare(db, "SELECT * FROM dt_test"),
+            ();
+            strict = true,
+        ) |> columntable
+        @test eltype(tbl.id) == Union{Missing,Int}
+        @test eltype(tbl.ts) == Union{Missing,String}
+        @test length(tbl.id) == 2
+        @test tbl.ts[1] === missing
+        @test tbl.ts[2] == "2024-01-01 00:00:00"
+
+        # non-strict
+        tbl2 = DBInterface.execute(db, "SELECT * FROM dt_test") |> columntable
+        @test eltype(tbl2.id) == Int
+        @test eltype(tbl2.ts) == Union{Missing,String}
+        @test length(tbl2.id) == 2
+        @test tbl2.ts[1] === missing
+        @test tbl2.ts[2] == "2024-01-01 00:00:00"
+    end
 end