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Query types with Option's support (#84)
* add return type support * add return type support * add return type support * add return type support * add return type support * cleanup * cleanup * add benchmark * move to faster hook types * move to faster hook types * move to faster hook types * move to faster hook types * check speed * cleanup * add fromQueryHook types * add fromQueryHook types * typed queries * typed queries * use monotimes * cleanup macros * cleanup macros * cleanup macros * cleanup macros * cleanup macros * cleanup macros * cleanup macros * cleanup macros * cleanup macros * cleanup macros * cleanup macros * cleanup macros * cleanup macros * cleanup macros * cleanup macros * simplify macros * simplify macros * simplify macros * simplify macros * reduce overhead * reduce overhead by using moves
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Lines changed: 579 additions & 29 deletions

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‎README.md‎

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@@ -241,6 +241,75 @@ let newId = query:
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```
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### Typed Queries
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Use `query(T):` when you want Ormin to deserialize selected columns directly into a named Nim type instead of returning the default tuple shape. This is useful at module boundaries where a named object, ref object, or scalar domain type is clearer than a tuple.
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For object results, selected column names must match fields on the destination type. Use `as` aliases when the database column name differs from the Nim field name:
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```nim
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type
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ThreadSummary = object
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id: int
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title: string
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let threads = query(ThreadSummary):
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select thread(id, name as title)
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orderby id
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```
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Selecting one column can map directly to a scalar type:
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```nim
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let names = query(string):
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select thread(name)
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```
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Queries that return a single row, such as a `limit 1` query, return one `T` instead of `seq[T]`:
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```nim
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let thread = query(ThreadSummary):
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select thread(id, name as title)
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where id == ?threadId
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limit 1
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```
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#### `fromQueryHook` Column Hooks
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Typed queries deserialize each selected column through `fromQueryHook`. You can overload this hook for your own field or scalar destination types:
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```nim
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import ormin/query_hooks
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type
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TitleLength = distinct int
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ThreadTitleSize = object
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id: int
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title: TitleLength
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proc fromQueryHook*(val: var TitleLength, value: string) =
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val = TitleLength(value.len)
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let rows = query(ThreadTitleSize):
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select thread(id, name as title)
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```
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If a hook needs to handle SQL `NULL` itself, accept a `DbValue[SourceType]`:
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```nim
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type
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NullableTitle = distinct string
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proc fromQueryHook*(val: var NullableTitle, value: DbValue[string]) =
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if value.isNull:
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val = NullableTitle("<untitled>")
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else:
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val = NullableTitle(value.value)
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```
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These are column deserialization hooks. In object typed queries, Ormin calls `fromQueryHook` separately for each selected column that maps to a destination field; it does not currently call a hook for the entire row object. For whole-row transformations, query into an intermediate typed result and convert it in regular Nim code.
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### JSON and Raw SQL
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JSON values can be spliced directly using `%` expressions. The `%` prefix tells Ormin to treat the following Nim expression as a `JsonNode` without conversion:

‎config.nims‎

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@@ -16,6 +16,7 @@ task test, "Run all test suite":
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exec "nim c -f -r tests/tfeature"
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exec "nim c -f -r tests/tcommon"
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exec "nim c -f -r -d:release tests/tquery_types"
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exec "nim c -f -r tests/tsqlite"
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exec "nim c -f -r tests/tdb_utils"
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exec "nim c -f -r tests/timportstatic"
@@ -34,6 +35,7 @@ task test_postgres, "Run PostgreSQL test suite":
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exec "nim c -f -d:nimDebugDlOpen -r -d:postgre tests/tfeature"
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exec "nim c -f -d:nimDebugDlOpen -r -d:postgre tests/tcommon"
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exec "nim c -f -d:nimDebugDlOpen -r -d:release -d:postgre tests/tquery_types"
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exec "nim c -f -d:nimDebugDlOpen -r -d:postgre tests/tpostgre"
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task buildexamples, "Build examples: chat and forum":

‎ormin.nimble‎

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# Package
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3-
version = "0.8.1"
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version = "0.9.0"
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author = "Araq"
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description = "Prepared SQL statement generator. A lightweight ORM."
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license = "MIT"
@@ -20,3 +20,4 @@ feature "examples":
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import std/os
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when fileExists("config.nims"):
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include "config.nims"
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‎ormin/ormin_postgre.nim‎

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@@ -1,6 +1,7 @@
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import strutils, db_connector/postgres, json, times
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import db_connector/db_common
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import query_hooks
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export db_common
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type
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pparams[idx-1] = $x
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parr[idx-1] = cstring(pparams[idx-1])
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template bindNullParam*(db: DbConn; s: PStmt; idx: int) =
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parr[idx-1] = cstring(nil)
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template bindParamJson*(db: DbConn; s: PStmt; idx: int; xx: JsonNode;
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t: typedesc) =
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let x = xx
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template bindResult*(db: DbConn; s: PStmt; idx: int; dest: var string;
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t: typedesc; name: string) =
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let src = pqgetvalue(queryResult, queryI, idx.cint)
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let srcLen = int(pqgetlength(queryResult, queryI, idx.cint))
134-
fillString(dest, src, srcLen)
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if pqgetisnull(queryResult, queryI, idx.cint) != 0:
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when defined(nimNoNilSeqs):
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setLen(dest, 0)
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else:
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dest = nil
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else:
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let src = pqgetvalue(queryResult, queryI, idx.cint)
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let srcLen = int(pqgetlength(queryResult, queryI, idx.cint))
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fillString(dest, src, srcLen)
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template bindResult*(db: DbConn; s: PStmt; idx: int; dest: float64;
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t: typedesc; name: string) =
@@ -162,6 +172,19 @@ template bindResult*(db: DbConn; s: PStmt; idx: int; dest: JsonNode;
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t: typedesc; name: string) =
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dest = parseJson($pqgetvalue(queryResult, queryI, idx.cint))
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175+
template bindResult*[T](db: DbConn; s: PStmt; idx: int; dest: var DbValue[T];
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t: typedesc; name: string) =
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if pqgetisnull(queryResult, queryI, idx.cint) != 0:
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dest.isNull = true
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else:
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dest.isNull = false
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when T is string:
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let src = pqgetvalue(queryResult, queryI, idx.cint)
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let srcLen = int(pqgetlength(queryResult, queryI, idx.cint))
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fillString(dest.value, src, srcLen)
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else:
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bindResult(db, s, idx, dest.value, t, name)
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template createJObject*(): untyped = newJObject()
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template createJArray*(): untyped = newJArray()
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else:
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bindToJson(db, s, idx, x, t, name)
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200+
template columnIsNull*(db: DbConn; s: PStmt; idx: int): bool =
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pqgetisnull(queryResult, queryI, idx.cint) != 0
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template bindToJson*(db: DbConn; s: PStmt; idx: int; obj: JsonNode;
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t: typedesc; name: string) =
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{.error: "invalid type for JSON object".}

‎ormin/ormin_sqlite.nim‎

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@@ -5,6 +5,7 @@ import json, times
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import db_connector/db_common
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import db_connector/sqlite3
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import query_hooks
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export db_common
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type
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cast[pointer](nil)
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else:
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cast[pointer](unsafeAddr(xs[0]))
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if bind_blob(s, idx.cint, blobPtr, xs.len.cint, SQLITE_STATIC) != SQLITE_OK:
49+
if bind_blob(s, idx.cint, blobPtr, xs.len.cint, SQLITE_TRANSIENT) != SQLITE_OK:
4950
dbError(db)
5051
elif t is int or t is int64 or t is bool:
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if bind_int64(s, idx.cint, x.int64) != SQLITE_OK: dbError(db)
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elif t is string:
53-
if bind_text(s, idx.cint, cstring(x), x.len.cint, SQLITE_STATIC) != SQLITE_OK:
54+
if bind_text(s, idx.cint, cstring(x), x.len.cint, SQLITE_TRANSIENT) != SQLITE_OK:
5455
dbError(db)
5556
elif t is float64:
5657
if bind_double(s, idx.cint, x) != SQLITE_OK:
@@ -61,15 +62,19 @@ template bindParam*(db: DbConn; s: PStmt; idx: int; x, t: untyped) =
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else:
6263
x.utc().format("yyyy-MM-dd HH:mm:ss")
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64-
if bind_text(s, idx.cint, cstring(xx), xx.len.cint, SQLITE_STATIC) != SQLITE_OK:
65+
if bind_text(s, idx.cint, cstring(xx), xx.len.cint, SQLITE_TRANSIENT) != SQLITE_OK:
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dbError(db)
6667
elif t is JsonNode:
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let xx = $x
68-
if bind_text(s, idx.cint, cstring(xx), xx.len.cint, SQLITE_STATIC) != SQLITE_OK:
69+
if bind_text(s, idx.cint, cstring(xx), xx.len.cint, SQLITE_TRANSIENT) != SQLITE_OK:
6970
dbError(db)
7071
else:
7172
{.error: "type mismatch for query argument at position " & $idx.}
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74+
template bindNullParam*(db: DbConn; s: PStmt; idx: int) =
75+
if bind_null(s, idx.cint) != SQLITE_OK:
76+
dbError(db)
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template bindParamJson*(db: DbConn; s: PStmt; idx: int; xx: JsonNode;
7479
t: typedesc) =
7580
let x = xx
@@ -86,7 +91,7 @@ template bindFromJson*(db: DbConn; s: PStmt; idx: int; x: JsonNode;
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t: typedesc[string]) =
8792
doAssert x.kind == JString
8893
let xs = x.str
89-
if bind_text(s, idx.cint, cstring(xs), xs.len.cint, SQLITE_STATIC) != SQLITE_OK:
94+
if bind_text(s, idx.cint, cstring(xs), xs.len.cint, SQLITE_TRANSIENT) != SQLITE_OK:
9095
dbError(db)
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9297
template bindFromJson*(db: DbConn; s: PStmt; idx: int; x: JsonNode;
@@ -118,7 +123,7 @@ template bindFromJson*(db: DbConn; s: PStmt; idx: int; x: JsonNode;
118123
dtStr[0 ..< i]
119124
else:
120125
dtStr
121-
if bind_text(s, idx.cint, cstring(dt), dt.len.cint, SQLITE_STATIC) != SQLITE_OK:
126+
if bind_text(s, idx.cint, cstring(dt), dt.len.cint, SQLITE_TRANSIENT) != SQLITE_OK:
122127
dbError(db)
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124129
template bindResult*(db: DbConn; s: PStmt; idx: int; dest: int;
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150155
template bindResult*(db: DbConn; s: PStmt; idx: int; dest: var string;
151156
t: typedesc; name: string) =
152-
let srcLen = column_bytes(s, idx.cint)
153-
let src = column_text(s, idx.cint)
154-
fillString(dest, src, srcLen)
157+
if column_type(s, idx.cint) == SQLITE_NULL:
158+
when defined(nimNoNilSeqs):
159+
setLen(dest, 0)
160+
else:
161+
dest = nil
162+
else:
163+
let srcLen = column_bytes(s, idx.cint)
164+
let src = column_text(s, idx.cint)
165+
fillString(dest, src, srcLen)
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156167
template bindResult*(db: DbConn; s: PStmt; idx: int; dest: var blobType;
157168
t: typedesc; name: string) =
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182193
let src = column_text(s, idx.cint)
183194
dest = parseJson($src)
184195

196+
template bindResult*[T](db: DbConn; s: PStmt; idx: int; dest: var DbValue[T];
197+
t: typedesc; name: string) =
198+
if column_type(s, idx.cint) == SQLITE_NULL:
199+
dest.isNull = true
200+
else:
201+
dest.isNull = false
202+
when T is string:
203+
let srcLen = column_bytes(s, idx.cint)
204+
let src = column_text(s, idx.cint)
205+
fillString(dest.value, src, srcLen)
206+
else:
207+
bindResult(db, s, idx, dest.value, t, name)
208+
185209
template createJObject*(): untyped = newJObject()
186210
template createJArray*(): untyped = newJArray()
187211

@@ -194,6 +218,9 @@ template bindResultJson*(db: DbConn; s: PStmt; idx: int; obj: JsonNode;
194218
else:
195219
bindToJson(db, s, idx, x, t, name)
196220

221+
template columnIsNull*(db: DbConn; s: PStmt; idx: int): bool =
222+
column_type(s, idx.cint) == SQLITE_NULL
223+
197224
template bindToJson*(db: DbConn; s: PStmt; idx: int; obj: JsonNode;
198225
t: typedesc; name: string) =
199226
{.error: "invalid type for JSON object".}

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