Add mixed affinity UPDATE, unify UUID behaviour (#95)

Author: mkgrgis

Makefile

@@ -15,7 +15,7 @@ OBJS = connection.o option.o deparse.o sqlite_query.o sqlite_fdw.o sqlite_data_n
 EXTENSION = sqlite_fdw
 DATA = sqlite_fdw--1.0.sql sqlite_fdw--1.0--1.1.sql
 
-REGRESS = extra/sqlite_fdw_post extra/float4 extra/float8 extra/int4 extra/int8 extra/numeric extra/join extra/limit extra/aggregates extra/prepare extra/select_having extra/select extra/insert extra/update extra/timestamp extra/encodings extra/bool extra/uuid sqlite_fdw type aggregate selectfunc 
+REGRESS = extra/sqlite_fdw_post extra/bitstring extra/bool extra/float4 extra/float8 extra/int4 extra/int8 extra/numeric extra/out_of_range extra/timestamp extra/uuid extra/join extra/limit extra/aggregates extra/prepare extra/select_having extra/select extra/insert extra/update extra/encodings sqlite_fdw type aggregate selectfunc 
 REGRESS_OPTS = --encoding=utf8
 
 SQLITE_LIB = sqlite3

README.md

@@ -36,11 +36,11 @@ Features
 - Support Bulk `INSERT` by using `batch_size` option
 - Support `INSERT`/`UPDATE` with generated column
 - Support `ON CONFLICT DO NOTHING`
-- Support mixed SQLite [data affinity](https://www.sqlite.org/datatype3.html) input and filtering (`SELECT`/`WHERE` usage) for such dataypes as
+- Support mixed SQLite [data affinity](https://www.sqlite.org/datatype3.html) input and filtering (`SELECT`/`WHERE` usage) for such data types as
 	- `timestamp`: `text` and `int`,
 	- `uuid`: `text`(32..39) and `blob`(16),
  	- `bool`: `text`(1..5) and `int`.
-- Support mixed SQLite [data affinity](https://www.sqlite.org/datatype3.html) output (`INSERT`/`UPDATE`) for such dataypes as
+- Support mixed SQLite [data affinity](https://www.sqlite.org/datatype3.html) output (`INSERT`/`UPDATE`) for such data types as
 	- `timestamp`: `text`(default) or `int`,
  	- `uuid`: `text`(36) or `blob`(16)(default).
 
@@ -55,7 +55,7 @@ Features
 - `mod()` is pushdowned. In PostgreSQL gives [argument-dependend data type](https://www.postgresql.org/docs/current/functions-math.html), but result from SQLite always [have `real` affinity](https://www.sqlite.org/lang_mathfunc.html#mod).
 - `upper`, `lower` and other character case functions are **not** pushed down because they does not work with UNICODE character in SQLite.
 - `WITH TIES` option is **not** pushed down.
-- Bit string `#` (XOR) operator is **not** pushed down becasuse there is no equal SQLite operator.
+- Bit string `#` (XOR) operator is **not** pushed down because there is no equal SQLite operator.
 
 ### Notes about pushdowning
 
@@ -69,7 +69,7 @@ Features
 - For `numeric` data type, `sqlite_fdw` use `sqlite3_column_double` to get value, while SQLite shell uses `sqlite3_column_text` to get value. Those 2 APIs may return different numeric value. Therefore, for `numeric` data type, the value returned from `sqlite_fdw` may different from the value returned from SQLite shell.
 - `sqlite_fdw` can return implementation-dependent order for column if the column is not specified in `ORDER BY` clause.
 - When the column type is `varchar array`, if the string is shorter than the declared length, values of type character will be space-padded; values of type `character varying` will simply store the shorter string.
-- [String literals for `boolean`](https://www.postgresql.org/docs/current/datatype-boolean.html) (`t`, `f`, `y`, `n`, `yes`, `no`, `on`, `off` etc. case insensetive) can be readed and filtred but cannot writed, because SQLite documentation recommends only `int` affinity values (`0` or `1`)  for boolean data and usually text boolean data belongs to legacy datasets.
+- [String literals for `boolean`](https://www.postgresql.org/docs/current/datatype-boolean.html) (`t`, `f`, `y`, `n`, `yes`, `no`, `on`, `off` etc. case insensitive) can be readed and filtred but cannot writed, because SQLite documentation recommends only `int` affinity values (`0` or `1`)  for boolean data and usually text boolean data belongs to legacy datasets.
 
 Also see [Limitations](#limitations)
 
@@ -227,7 +227,7 @@ In OS `sqlite_fdw` works as executed code with permissions of user of PostgreSQL
 in SQLite (mixed affinity case). Updated and inserted values will have this affinity. Default preferred SQLite affinity for `timestamp` and `uuid` PostgreSQL data types is `text`.
 
   - Use `INT` value for SQLite column (epoch Unix Time) to be treated/visualized as `timestamp` in PostgreSQL.
-  - Use `BLOB` value for SQLite column to be treated/visualized as `uuid` in PostgreSQL 14+.
+  - Use `BLOB` value for SQLite column to be treated/visualized as `uuid`.
 
 - **key** as *boolean*, optional, default *false*
 
@@ -300,7 +300,7 @@ sqlite_fdw_version
 Identifier case handling
 ------------------------
 
-PostgreSQL folds identifiers to lower case by default, SQLite is case insensetive by default
+PostgreSQL folds identifiers to lower case by default, SQLite is case insensitive by default
 and doesn't differ uppercase and lowercase ASCII base latin letters. It's important
 to be aware of potential issues with table and column names.
 
@@ -533,7 +533,7 @@ Limitations
 - For `sum` function of SQLite, output of `sum(bigint)` is `integer` value. If input values are big, the overflow error may occurs on SQLite because it overflow within the range of signed 64bit. For PostgreSQL, it can calculate as over the precision of `bigint`, so overflow does not occur.
 - SQLite promises to preserve the 15 most significant digits of a floating point value. The big value which exceed 15 most significant digits may become different value after inserted.
 - SQLite does not support `numeric` type as PostgreSQL. Therefore, it does not allow to store numbers with too high precision and scale. Error out of range occurs.
-- SQLite does not support special values for IEEE 754-2008 numbers such as `NaN`, `+Infinity` and `-Infinity` in SQL expressions with numeric context. Also SQLite can not store this values with `real` [affinity](https://www.sqlite.org/datatype3.html). In opposite to SQLite, PostgreSQL can store special values in columns belongs to `real` datatype family such as `float` or `double precision` and use arithmetic comparation for this values. In oppose to PostgreSQL, SQLite stores `NaN`, `+Infinity` and `-Infinity` as a text values. Also conditions with special literals (such as ` n < '+Infinity'` or ` m > '-Infinity'` ) isn't numeric conditions in SQLite and gives unexpected result after pushdowning in oppose to internal PostgreSQL calculations. During `INSERT INTO ... SELECT` or in `WHERE` conditions `sqlite_fdw` uses given by PostgreSQL standard case sensetive literals **only** in follow forms: `NaN`, `-Infinity`, `Infinity`, not original strings from `WHERE` condition. *This can caused selecting issues*.
+- SQLite does not support special values for IEEE 754-2008 numbers such as `NaN`, `+Infinity` and `-Infinity` in SQL expressions with numeric context. Also SQLite can not store this values with `real` [affinity](https://www.sqlite.org/datatype3.html). In opposite to SQLite, PostgreSQL can store special values in columns belongs to `real` datatype family such as `float` or `double precision` and use arithmetic comparation for this values. In oppose to PostgreSQL, SQLite stores `NaN`, `+Infinity` and `-Infinity` as a text values. Also conditions with special literals (such as ` n < '+Infinity'` or ` m > '-Infinity'` ) isn't numeric conditions in SQLite and gives unexpected result after pushdowning in oppose to internal PostgreSQL calculations. During `INSERT INTO ... SELECT` or in `WHERE` conditions `sqlite_fdw` uses given by PostgreSQL standard case sensitive literals **only** in follow forms: `NaN`, `-Infinity`, `Infinity`, not original strings from `WHERE` condition. *This can caused selecting issues*.
 
 ### Boolean values
 - `sqlite_fdw` boolean values support exists only for `bool` columns in foreign table. SQLite documentation recommends to store boolean as value with `integer` [affinity](https://www.sqlite.org/datatype3.html). `NULL` isn't converted, 1 converted to `true`, all other `NOT NULL` values converted to `false`. During `SELECT ... WHERE condition_column` condition converted only to `condition_column`.
@@ -542,17 +542,17 @@ Limitations
 ### UUID values
 - `sqlite_fdw` UUID values support exists only for `uuid` columns in foreign table. SQLite documentation recommends to store UUID as value with both `blob` and `text` [affinity](https://www.sqlite.org/datatype3.html). `sqlite_fdw` can pushdown both reading and filtering both `text` and `blob` values.
 - Expected affinity of UUID value in SQLite table determined by `column_type` option of the column
-for `INSERT` and `UPDATE` commands. In PostgreSQL 14- only `text` data affinity is availlable, PostgreSQL 14+ supports also `blob` data affinity.
+for `INSERT` and `UPDATE` commands. PostgreSQL supports both `blob` and `text` [affinity](https://www.sqlite.org/datatype3.html).
 
 ### bit and varbit support
 - `sqlite_fdw` PostgreSQL `bit`/`varbit` values support based on `int` SQLite data affinity, because there is no per bit operations for SQLite `blob` affinity data. Maximum SQLite `int` affinity value is 8 bytes length, hence maximum `bit`/`varbit` values length is 64 bits.
-- `sqlite_fdw` doesn't pushdown `#` (XOR) operator becasuse there is no equal SQLite operator.
+- `sqlite_fdw` doesn't pushdown `#` (XOR) operator because there is no equal SQLite operator.
 
 Tests
 -----
 Test directory have structure as following:
 
-```sql
+```
 +---sql
 |   +---12.16
 |   |       filename1.sql

deparse.c

@@ -164,6 +164,7 @@ static void sqlite_get_relation_column_alias_ids(Var *node, RelOptInfo *foreignr
 static char *sqlite_quote_identifier(const char *s, char q);
 static bool sqlite_contain_immutable_functions_walker(Node *node, void *context);
 static bool sqlite_is_valid_type(Oid type);
+static int preferred_sqlite_affinity (Oid relid, int varattno);
 
 /*
  * Append remote name of specified foreign table to buf.
@@ -2107,6 +2108,9 @@ sqlite_deparse_column_ref(StringInfo buf, int varno, int varattno, PlannerInfo *
 	}
 }
 
+/*
+ * Get column option with optionname for a variable attribute in deparsing context
+ */
 static char *
 sqlite_deparse_column_option(int varno, int varattno, PlannerInfo *root, char *optionname)
 {
@@ -2296,6 +2300,36 @@ sqlite_deparse_update(StringInfo buf, PlannerInfo *root,
 	}
 }
 
+/*
+ * Preferred SQLite affinity from "column_type" foreign column option
+ * SQLITE_NULL if no value or no normal value
+ */
+int
+preferred_sqlite_affinity (Oid relid, int varattno)
+{
+	char	   *coltype = NULL;
+	List	   *options;
+	ListCell   *lc;
+
+	elog(DEBUG4, "sqlite_fdw : %s ", __func__);
+	if (varattno == 0)
+		return SQLITE_NULL;
+
+	options = GetForeignColumnOptions(relid, varattno);
+	foreach(lc, options)
+	{
+		DefElem	*def = (DefElem *) lfirst(lc);
+
+		if (strcmp(def->defname, "column_type") == 0)
+		{
+			coltype = defGetString(def);
+			elog(DEBUG4, "column type = %s", coltype);
+			break;
+		}
+	}
+	return sqlite_affinity_code(coltype);
+}
+
 /*
  * deparse remote UPDATE statement
  *
@@ -2346,7 +2380,11 @@ sqlite_deparse_direct_update_sql(StringInfo buf, PlannerInfo *root,
 	forboth(lc, targetlist, lc2, targetAttrs)
 	{
 		int			attnum = lfirst_int(lc2);
+		int			preferred_affinity = SQLITE_NULL;
 		TargetEntry *tle;
+		RangeTblEntry *rte;
+		bool		special_affinity = false;
+		Oid			pg_attyp;
 #if (PG_VERSION_NUM >= 140000)
 		tle = lfirst_node(TargetEntry, lc);
 
@@ -2366,8 +2404,25 @@ sqlite_deparse_direct_update_sql(StringInfo buf, PlannerInfo *root,
 		first = false;
 
 		sqlite_deparse_column_ref(buf, rtindex, attnum, root, false, true);
+
+		/* Get RangeTblEntry from array in PlannerInfo. */
+		rte = planner_rt_fetch(rtindex, root);
+		pg_attyp = get_atttype(rte->relid, attnum);
+		preferred_affinity = preferred_sqlite_affinity(rte->relid, attnum);
+
 		appendStringInfoString(buf, " = ");
+		if (pg_attyp == UUIDOID && preferred_affinity == SQLITE3_TEXT)
+		{
+			appendStringInfo(buf, "sqlite_fdw_uuid_str(");
+			special_affinity = true;
+		}
 		sqlite_deparse_expr((Expr *) tle->expr, &context);
+
+		if (special_affinity)
+		{
+			elog(DEBUG4, "sqlite_fdw : aff %d\n", preferred_affinity);
+			appendStringInfoString(buf, ")");
+		}
 	}
 
 	sqlite_reset_transmission_modes(nestlevel);