\nlet users = Table(“users”)
\nlet email = Expression
\nlet name = Expression
do {
\n for user in try db.prepare(users) {
\n print(user)
\n }
\n} catch {
\n print(“\u67e5\u8a62\u5931\u6557: \\(error)”)
\n}
\n“`<\/p>\n
\u5982\u679c\u4f60\u60f3\u9032\u884c\u66f4\u8907\u96dc\u7684\u67e5\u8a62\uff0c\u53ef\u4ee5\u4f7f\u7528\u93c8\u5f0f\u8abf\u7528\u7684\u65b9\u5f0f\u4f86\u7d44\u5408\u67e5\u8a62\u689d\u4ef6\uff1a<\/p>\n
“`swift
\nlet query = users.select(email) \/\/ SELECT “email” FROM “users”
\n .filter(name != nil) \/\/ WHERE “name” IS NOT NULL
\n .order(email.desc, name) \/\/ ORDER BY “email” DESC, “name”
\n .limit(5, offset: 1) \/\/ LIMIT 5 OFFSET 1
\n“`<\/p>\n
\u96d6\u7136\u9019\u6a23\u7684\u5beb\u6cd5\u5f88\u65b9\u4fbf\uff0c\u4f46\u5c0d\u65bc\u719f\u6089 SQL \u8a9e\u6cd5\u7684\u958b\u767c\u8005\u4f86\u8aaa\uff0c\u9084\u662f\u53ef\u80fd\u6703\u611f\u5230\u4e0d\u7fd2\u6163\u3002\u5e78\u597d\uff0cSQLite.swift \u652f\u63f4\u539f\u751f SQL \u8a9e\u6cd5\uff0c\u8b93\u6211\u5011\u53ef\u4ee5\u66f4\u9748\u6d3b\u5730\u64cd\u4f5c\u6578\u64da\u3002<\/p>\n
\u4f7f\u7528 SQL \u8a9e\u6cd5\u9032\u884c\u67e5\u8a62<\/h1>\n
\u5728\u9019\u90e8\u5206\uff0c\u6211\u5011\u5c07\u4f7f\u7528 SQL \u8a9e\u6cd5\u4f86\u67e5\u8a62\u76f8\u540c\u7522\u54c1\u7684\u50f9\u683c\u4e26\u9032\u884c\u52a0\u7e3d\u3002\u9996\u5148\uff0c\u6211\u5011\u9700\u8981\u64b0\u5beb\u4e00\u500b\u57fa\u672c\u7684 SELECT \u8a9e\u53e5\u3002<\/p>\n
\u57fa\u672c SELECT \u4f7f\u7528\u793a\u7bc4<\/h2>\n
\u4ee5\u4e0b\u662f\u4f7f\u7528 SQL \u8a9e\u6cd5\u67e5\u8a62\u7522\u54c1\u53ca\u5176\u50f9\u683c\u7684\u4f8b\u5b50\uff1a<\/p>\n
![\"\u793a\u7bc4\u67e5\u8a62\u7522\u54c1\u53ca\u50f9\u683c\u7684\u7d50\u69cb\"](\"https:\/\/upload.cc\/i1\/2018\/10\/25\/ixThbt.png\" "\\"\\"")
<\/p>\n
“`swift
\nfor user in try db.prepare(“SELECT DISTINCT product, price FROM stock”) {
\n print(user)
\n}
\n“`<\/p>\n
\u9019\u6bb5\u7a0b\u5f0f\u78bc\u5c07\u8fd4\u56de\u6bcf\u500b\u7522\u54c1\u7684\u540d\u7a31\u53ca\u5176\u50f9\u683c\uff0c\u4f8b\u5982\uff1a<\/p>\n
“`swift
\n[\u5927\u6d77\u87ba, 900]\n[\u5927\u6d77\u87ba, 99]\n[\u6b50\u62c9, 250]\n[\u7f8e\u597d, 250]\n“`<\/p>\n
\u7136\u800c\uff0c\u82e5\u67d0\u500b\u7522\u54c1\u6709\u591a\u500b\u50f9\u683c\uff0c\u6211\u5011\u9700\u8981\u5c07\u5176\u52a0\u7e3d\u3002\u53ef\u4ee5\u4f7f\u7528 `SUM` \u51fd\u6578\u548c `GROUP BY` \u5b50\u53e5\u4f86\u5be6\u73fe\uff1a<\/p>\n
“`swift
\nfor user in try db.prepare(“SELECT product, SUM(price) AS total_price FROM stock GROUP BY product”) {
\n print(user)
\n}
\n“`<\/p>\n
\u9019\u6a23\u53ef\u4ee5\u5f97\u5230\u6bcf\u500b\u7522\u54c1\u7684\u7e3d\u50f9\u683c\uff0c\u5f97\u5230\u7684\u7d50\u679c\u5982\u4e0b\uff1a<\/p>\n
“`swift
\n[\u5927\u6d77\u87ba, 999]\n[\u6b50\u62c9, 250]\n[\u7f8e\u597d, 250]\n“`<\/p>\n
\u9019\u6a23\u7684\u64cd\u4f5c\u4e0d\u50c5\u7c21\u5316\u4e86\u67e5\u8a62\u904e\u7a0b\uff0c\u540c\u6642\u4e5f\u80fd\u8b93\u6211\u5011\u66f4\u65b9\u4fbf\u5730\u9032\u884c\u6578\u64da\u5206\u6790\u3002<\/p>\n
\u932f\u8aa4\u6392\u9664<\/h1>\n
\u5728\u4f7f\u7528 SQLite \u9032\u884c\u67e5\u8a62\u6642\uff0c\u5e38\u898b\u7684\u932f\u8aa4\u6709\uff1a
\n– **\u8a9e\u6cd5\u932f\u8aa4**\uff1a\u8acb\u6aa2\u67e5 SQL \u8a9e\u6cd5\u662f\u5426\u6b63\u78ba\uff0c\u7279\u5225\u662f\u5f15\u865f\u3001\u62ec\u865f\u7b49\u7b26\u865f\u3002
\n– **\u8cc7\u6599\u5eab\u672a\u9023\u63a5**\uff1a\u78ba\u4fdd\u8cc7\u6599\u5eab\u5df2\u6b63\u78ba\u521d\u59cb\u5316\u548c\u9023\u63a5\u3002
\n– **\u8868\u540d\u6216\u5217\u540d\u932f\u8aa4**\uff1a\u8acb\u78ba\u8a8d\u4f60\u6240\u4f7f\u7528\u7684\u8868\u540d\u548c\u5217\u540d\u8207\u8cc7\u6599\u5eab\u4e2d\u7684\u4e00\u81f4\u3002<\/p>\n
\u5ef6\u4f38\u61c9\u7528<\/h1>\n
\u4e86\u89e3 SQLite \u7684\u57fa\u672c\u67e5\u8a62\u5f8c\uff0c\u4f60\u53ef\u4ee5\u9032\u4e00\u6b65\u5b78\u7fd2\u5982\u4f55\u7d50\u5408 SwiftUI \u6216 UIKit \u4f86\u986f\u793a\u67e5\u8a62\u7d50\u679c\uff0c\u4e26\u5efa\u7acb\u66f4\u8907\u96dc\u7684\u6578\u64da\u9a45\u52d5\u61c9\u7528\u7a0b\u5e8f\u3002<\/p>\n
\n
![\"\u6559\u5b78\u5716\u7247\"](\"https:\/\/badgameshow.com\/steven\/wp-content\/uploads\/2020\/11\/cup-1-1.png\" "\\"\\"")
<\/a><\/p>\n