Use REAL not FLOAT as SQLite column type (#680)

* Use REAL not FLOAT as SQLite column type, refs #645
* Fix for REAL columns by CSV --detect-types

Refs https://github.com/simonw/sqlite-utils/issues/645#issuecomment-3568947189

* Removed note about strict and REAL

docs/changelog.rst

@@ -10,6 +10,7 @@ Unreleased
 ----------
 
 - The ``table.insert_all()`` and ``table.upsert_all()`` methods can now accept an iterator of lists or tuples as an alternative to dictionaries. The first item should be a list/tuple of column names. See :ref:`python_api_insert_lists` for details. (:issue:`672`)
+- **Breaking change:** The default floating point column type has been changed from ``FLOAT`` to ``REAL``, which is the correct SQLite type for floating point values. This affects auto-detected columns when inserting data. (:issue:`645`)
 
 .. _v4_0a0:
 

docs/cli-reference.rst

@@ -457,8 +457,8 @@ See :ref:`cli_transform_table`.
               --rename column2 column_renamed
 
     Options:
-      --type <TEXT CHOICE>...         Change column type to INTEGER, TEXT, FLOAT or
-                                      BLOB
+      --type <TEXT CHOICE>...         Change column type to INTEGER, TEXT, FLOAT,
+                                      REAL or BLOB
       --drop TEXT                     Drop this column
       --rename <TEXT TEXT>...         Rename this column to X
       -o, --column-order TEXT         Reorder columns
@@ -1142,7 +1142,7 @@ See :ref:`cli_add_column`.
 ::
 
     Usage: sqlite-utils add-column [OPTIONS] PATH TABLE COL_NAME
-                          [[integer|int|float|text|str|blob|bytes]]
+                          [[integer|int|float|real|text|str|blob|bytes]]
 
       Add a column to the specified table
 

docs/cli.rst

@@ -1247,7 +1247,7 @@ To stop inserting after a specified number of records - useful for getting a fas
 
 A progress bar is displayed when inserting data from a file. You can hide the progress bar using the ``--silent`` option.
 
-By default every column inserted from a CSV or TSV file will be of type ``TEXT``. To automatically detect column types - resulting in a mix of ``TEXT``, ``INTEGER`` and ``FLOAT`` columns, use the ``--detect-types`` option (or its shortcut ``-d``).
+By default every column inserted from a CSV or TSV file will be of type ``TEXT``. To automatically detect column types - resulting in a mix of ``TEXT``, ``INTEGER`` and ``REAL`` columns, use the ``--detect-types`` option (or its shortcut ``-d``).
 
 For example, given a ``creatures.csv`` file containing this:
 
@@ -1274,7 +1274,7 @@ Will produce this schema:
     CREATE TABLE "creatures" (
        "name" TEXT,
        "age" INTEGER,
-       "weight" FLOAT
+       "weight" REAL
     );
 
 You can set the ``SQLITE_UTILS_DETECT_TYPES`` environment variable if you want ``--detect-types`` to be the default behavior:
@@ -1589,7 +1589,7 @@ This will result in the following schema:
     CREATE TABLE "images" (
         "path" TEXT PRIMARY KEY,
         "md5" TEXT,
-        "mtime" FLOAT
+        "mtime" REAL
     );
 
 Note that there's no ``content`` column here at all - if you specify custom columns using ``-c`` you need to include ``-c content`` to create that column.
@@ -1888,8 +1888,8 @@ The type of the returned values will be taken into account when creating the new
 
     CREATE TABLE "places" (
         "location" TEXT,
-        "latitude" FLOAT,
-        "longitude" FLOAT
+        "latitude" REAL,
+        "longitude" REAL
     );
 
 The code function can also return ``None``, in which case its output will be ignored. You can drop the original column at the end of the operation by adding ``--drop``.

docs/python-api.rst

@@ -548,7 +548,7 @@ This will create a table with the following schema:
         "id" INTEGER PRIMARY KEY,
         "name" TEXT,
         "age" INTEGER,
-        "weight" FLOAT
+        "weight" REAL
     )
 
 .. _python_api_explicit_create:
@@ -1271,11 +1271,11 @@ You can specify the ``col_type`` argument either using a SQLite type as a string
 
 The ``col_type`` is optional - if you omit it the type of ``TEXT`` will be used.
 
-SQLite types you can specify are ``"TEXT"``, ``"INTEGER"``, ``"FLOAT"`` or ``"BLOB"``.
+SQLite types you can specify are ``"TEXT"``, ``"INTEGER"``, ``"FLOAT"``, ``"REAL"`` or ``"BLOB"``.
 
 If you pass a Python type, it will be mapped to SQLite types as shown here::
 
-    float: "FLOAT"
+    float: "REAL"
     int: "INTEGER"
     bool: "INTEGER"
     str: "TEXT"
@@ -1294,12 +1294,9 @@ If you pass a Python type, it will be mapped to SQLite types as shown here::
     np.uint16: "INTEGER"
     np.uint32: "INTEGER"
     np.uint64: "INTEGER"
-    np.float16: "FLOAT"
-    np.float32: "FLOAT"
-    np.float64: "FLOAT"
-
-.. note::
-    In sqlite-utils 3.x ``FLOAT`` is used for floating point columns when the correct column type is actually ``REAL``. If you specify ``strict=True`` tables created in strict mode will use the correct column type of ``REAL`` instead. We plan to change this behavior in ``sqlite-utils`` 4.x to always use ``REAL``, but this will represent a minor breaking change and so is being held for the next major release, see issue :issue:`645`.
+    np.float16: "REAL"
+    np.float32: "REAL"
+    np.float64: "REAL"
 
 You can also add a column that is a foreign key reference to another table using the ``fk`` parameter: