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sqliteviz/src/lib/database/_statements.js
lana-k 99a10225a3 CSV import as a table and db connection rework
- Add csv to existing db #32
- [RFE] Simplify working with temporary tables #53
2021-05-24 19:40:47 +02:00

91 lines
2.6 KiB
JavaScript

import sqliteParser from 'sqlite-parser'
export default {
* generateChunks (arr, size) {
const count = Math.ceil(arr.length / size)
for (let i = 0; i <= count - 1; i++) {
const start = size * i
const end = start + size
yield arr.slice(start, end)
}
},
getInsertStmt (tabName, columns) {
const colList = `"${columns.join('", "')}"`
const params = columns.map(() => '?').join(', ')
return `INSERT INTO "${tabName}" (${colList}) VALUES (${params});`
},
getCreateStatement (tabName, columns, values) {
let result = `CREATE table "${tabName}"(`
columns.forEach((col, index) => {
// Get the first row of values to determine types
const value = values[0][index]
let type = ''
switch (typeof value) {
case 'number': {
type = 'REAL'
break
}
case 'boolean': {
type = 'INTEGER'
break
}
case 'string': {
type = 'TEXT'
break
}
default: type = 'TEXT'
}
result += `"${col}" ${type}, `
})
result = result.replace(/,\s$/, ');')
return result
},
getAst (sql) {
// There is a bug is sqlite-parser
// It throws an error if tokenizer has an arguments:
// https://github.com/codeschool/sqlite-parser/issues/59
const fixedSql = sql
.replace(/(tokenize=[^,]+)"tokenchars=.+?"/, '$1')
.replace(/(tokenize=[^,]+)"remove_diacritics=.+?"/, '$1')
.replace(/(tokenize=[^,]+)"separators=.+?"/, '$1')
.replace(/tokenize=.+?(,|\))/, 'tokenize=unicode61$1')
return sqliteParser(fixedSql)
},
/*
* Return an array of columns with name and type. E.g.:
* [
* { name: 'id', type: 'INTEGER' },
* { name: 'title', type: 'NVARCHAR(30)' },
* ]
*/
getColumns (sql) {
const columns = []
const ast = this.getAst(sql)
const columnDefinition = ast.statement[0].format === 'table'
? ast.statement[0].definition
: ast.statement[0].result.args.expression // virtual table
columnDefinition.forEach(item => {
if (item.variant === 'column' && ['identifier', 'definition'].includes(item.type)) {
let type = item.datatype ? item.datatype.variant : 'N/A'
if (item.datatype && item.datatype.args) {
type = type + '(' + item.datatype.args.expression[0].value
if (item.datatype.args.expression.length === 2) {
type = type + ', ' + item.datatype.args.expression[1].value
}
type = type + ')'
}
columns.push({ name: item.name, type: type })
}
})
return columns
}
}