Readme
Port of blakeembrey/sql-template-tag for usage in val.town.
import { sqlite } from "https://esm.town/v/std/sqlite"
import { sql, zip } from "https://esm.town/v/pomdtr/sql"
const query = sql`SELECT * FROM books WHERE author = ${author}`;
console.log(query.sql) // => "SELECT * FROM books WHERE author = ?"
console.log(query.args) // => [author]
const res = await sqlite.execute(query)
console.table(zip(res))
For advanced usage (ex: nesting queries), refer to the project readme.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
import type { InValue, sqlite } from "https://esm.town/v/std/sqlite";
import { zip as zip2 } from "npm:lodash-es@4.17.21";
/**
* Supported value or SQL instance.
*/
type RawValue = InValue | Sql;
/**
* A SQL instance can be nested within each other to build SQL strings.
*/
class Sql {
readonly values: InValue[];
readonly strings: string[];
constructor(rawStrings: readonly string[], rawValues: readonly RawValue[]) {
if (rawStrings.length - 1 !== rawValues.length) {
if (rawStrings.length === 0) {
throw new TypeError("Expected at least 1 string");
}
throw new TypeError(
`Expected ${rawStrings.length} strings to have ${rawStrings.length - 1} values`,
);
}
const valuesLength = rawValues.reduce<number>(
(len, value) => len + (value instanceof Sql ? value.values.length : 1),
0,
);
this.values = new Array(valuesLength);
this.strings = new Array(valuesLength + 1);
this.strings[0] = rawStrings[0];
// Iterate over raw values, strings, and children. The value is always
// positioned between two strings, e.g. `index + 1`.
let i = 0,
pos = 0;
while (i < rawValues.length) {
const child = rawValues[i++];
const rawString = rawStrings[i];
// Check for nested `sql` queries.
if (child instanceof Sql) {
// Append child prefix text to current string.
this.strings[pos] += child.strings[0];
let childIndex = 0;
while (childIndex < child.values.length) {
this.values[pos++] = child.values[childIndex++];
this.strings[pos] = child.strings[childIndex];
}
// Append raw string to current string.
this.strings[pos] += rawString;
} else {
this.values[pos++] = child;
this.strings[pos] = rawString;
}
}
}
get sql() {
const len = this.strings.length;
let i = 1;
let value = this.strings[0];
while (i < len) value += `?${this.strings[i++]}`;
return value;
}
get args() {
return this.values;
}
toJSON() {
return {
sql: this.sql,
args: this.values,
};
}
}
/**
* Create a SQL query for a list of values.
*/
export function join(
values: readonly RawValue[],
separator = ",",
prefix = "",
suffix = "",
) {
if (values.length === 0) {
throw new TypeError(
"Expected `join([])` to be called with an array of multiple elements, but got an empty array",
);
}
return new Sql(
👆 This is a val. Vals are TypeScript snippets of code, written in the browser and run on our servers. Create scheduled functions, email yourself, and persist small pieces of data — all from the browser.