pg qa

go.mod

@@ -36,11 +36,13 @@ require (
 	github.com/joho/godotenv v1.5.1 // indirect
 	github.com/kr/pretty v0.3.1 // indirect
 	github.com/kr/text v0.2.0 // indirect
+	github.com/lib/pq v1.10.9 // indirect
 	github.com/mailru/easyjson v0.9.0 // indirect
 	github.com/mbleigh/raymond v0.0.0-20250414171441-6b3a58ab9e0a // indirect
 	github.com/milvus-io/milvus-proto/go-api/v2 v2.4.10-0.20240819025435-512e3b98866a // indirect
 	github.com/milvus-io/milvus-sdk-go/v2 v2.4.2 // indirect
 	github.com/ollama/ollama v0.6.5 // indirect
+	github.com/pgvector/pgvector-go v0.3.0 // indirect
 	github.com/pkg/errors v0.9.1 // indirect
 	github.com/rogpeppe/go-internal v1.13.1 // indirect
 	github.com/tidwall/gjson v1.18.0 // indirect

go.sum

@@ -174,6 +174,8 @@ github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
 github.com/labstack/echo/v4 v4.5.0/go.mod h1:czIriw4a0C1dFun+ObrXp7ok03xON0N1awStJ6ArI7Y=
 github.com/labstack/gommon v0.3.0/go.mod h1:MULnywXg0yavhxWKc+lOruYdAhDwPK9wf0OL7NoOu+k=
+github.com/lib/pq v1.10.9 h1:YXG7RB+JIjhP29X+OtkiDnYaXQwpS4JEWq7dtCCRUEw=
+github.com/lib/pq v1.10.9/go.mod h1:AlVN5x4E4T544tWzH6hKfbfQvm3HdbOxrmggDNAPY9o=
 github.com/magiconair/properties v1.8.0/go.mod h1:PppfXfuXeibc/6YijjN8zIbojt8czPbwD3XqdrwzmxQ=
 github.com/mailru/easyjson v0.9.0 h1:PrnmzHw7262yW8sTBwxi1PdJA3Iw/EKBa8psRf7d9a4=
 github.com/mailru/easyjson v0.9.0/go.mod h1:1+xMtQp2MRNVL/V1bOzuP3aP8VNwRW55fQUto+XFtTU=
@@ -212,6 +214,8 @@ github.com/onsi/ginkgo v1.10.3/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+
 github.com/onsi/gomega v1.7.1/go.mod h1:XdKZgCCFLUoM/7CFJVPcG8C1xQ1AJ0vpAezJrB7JYyY=
 github.com/opentracing/opentracing-go v1.1.0/go.mod h1:UkNAQd3GIcIGf0SeVgPpRdFStlNbqXla1AfSYxPUl2o=
 github.com/pelletier/go-toml v1.2.0/go.mod h1:5z9KED0ma1S8pY6P1sdut58dfprrGBbd/94hg7ilaic=
+github.com/pgvector/pgvector-go v0.3.0 h1:Ij+Yt78R//uYqs3Zk35evZFvr+G0blW0OUN+Q2D1RWc=
+github.com/pgvector/pgvector-go v0.3.0/go.mod h1:duFy+PXWfW7QQd5ibqutBO4GxLsUZ9RVXhFZGIBsWSA=
 github.com/pingcap/errors v0.11.4/go.mod h1:Oi8TUi2kEtXXLMJk9l1cGmz20kV3TaQ0usTwv5KuLY8=
 github.com/pkg/diff v0.0.0-20210226163009-20ebb0f2a09e/go.mod h1:pJLUxLENpZxwdsKMEsNbx1VGcRFpLqf3715MtcvvzbA=
 github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=

pgvector.sql

+
+
+
+
+create table public.qa (
+  id bigint generated by default as identity not null,
+  created_at timestamp with time zone not null default now(),
+  user_id bigint null,
+  username text null,
+  question text null,
+  answer text null,
+  constraint qa_pkey primary key (id)
+) TABLESPACE pg_default;
+
+
+
+create view public.latest_qa as
+select distinct
+  on (qa.user_id) qa.id,
+  qa.created_at,
+  qa.user_id,
+  qa.username,
+  qa.question,
+  qa.answer
+from
+  qa
+order by
+  qa.user_id,
+  qa.created_at desc;
\ No newline at end of file

qa.go

+package main
+
+import (
+	"context"
+	"database/sql"
+	"flag"
+	"fmt"
+	"log"
+	"time"
+
+	_ "github.com/lib/pq"
+)
+
+var (
+    connString = flag.String("dbconn", "", "database connection string")
+)
+
+// QA 结构体表示 qa 表的记录
+type QA struct {
+    ID        int64         // 主键
+    CreatedAt time.Time     // 创建时间
+    UserID    *int64        // 可空的用户 ID
+    Username  *string       // 可空的用户名
+    Question  *string       // 可空的问题
+    Answer    *string       // 可空的答案
+}
+
+// QAStore 定义 DAO 接口
+type QAStore interface {
+    // GetLatestQA 从 latest_qa 视图读取指定 user_id 的最新记录
+    GetLatestQA(ctx context.Context, userID *int64) ([]QA, error)
+    // WriteQA 插入或更新 qa 表记录
+    WriteQA(ctx context.Context, qa QA) (int64, error)
+}
+
+// qaStore 是 QAStore 接口的实现
+type qaStore struct {
+    db *sql.DB
+}
+
+// NewQAStore 创建新的 QAStore 实例
+func NewQAStore(db *sql.DB) QAStore {
+    return &qaStore{db: db}
+}
+
+// GetLatestQA 从 latest_qa 视图读取数据
+func (s *qaStore) GetLatestQA(ctx context.Context, userID *int64) ([]QA, error) {
+    query := `
+        SELECT id, created_at, user_id, username, question, answer
+        FROM latest_qa
+        WHERE user_id = $1 OR (user_id IS NULL AND $1 IS NULL)`
+    args := []interface{}{userID}
+    if userID == nil {
+        args = []interface{}{nil}
+    }
+
+    rows, err := s.db.QueryContext(ctx, query, args...)
+    if err != nil {
+        return nil, fmt.Errorf("query latest_qa: %w", err)
+    }
+    defer rows.Close()
+
+    var results []QA
+    for rows.Next() {
+        var qa QA
+        var userIDVal sql.NullInt64
+        var username, question, answer sql.NullString
+        if err := rows.Scan(&qa.ID, &qa.CreatedAt, &userIDVal, &username, &question, &answer); err != nil {
+            return nil, fmt.Errorf("scan row: %w", err)
+        }
+        if userIDVal.Valid {
+            qa.UserID = &userIDVal.Int64
+        }
+        if username.Valid {
+            qa.Username = &username.String
+        }
+        if question.Valid {
+            qa.Question = &question.String
+        }
+        if answer.Valid {
+            qa.Answer = &answer.String
+        }
+        results = append(results, qa)
+    }
+    if err := rows.Err(); err != nil {
+        return nil, fmt.Errorf("row iteration: %w", err)
+    }
+    return results, nil
+}
+
+// WriteQA 插入或更新 qa 表记录
+func (s *qaStore) WriteQA(ctx context.Context, qa QA) (int64, error) {
+    if qa.ID != 0 {
+        // 更新记录
+        query := `
+            UPDATE qa
+            SET user_id = $1, username = $2, question = $3, answer = $4
+            WHERE id = $5
+            RETURNING id`
+        var updatedID int64
+        err := s.db.QueryRowContext(ctx, query, qa.UserID, qa.Username, qa.Question, qa.Answer, qa.ID).Scan(&updatedID)
+        if err == sql.ErrNoRows {
+            return 0, fmt.Errorf("no record found with id %d", qa.ID)
+        }
+        if err != nil {
+            return 0, fmt.Errorf("update qa: %w", err)
+        }
+        return updatedID, nil
+    }
+
+    // 插入新记录
+    query := `
+        INSERT INTO qa (user_id, username, question, answer)
+        VALUES ($1, $2, $3, $4)
+        RETURNING id`
+    var newID int64
+    err := s.db.QueryRowContext(ctx, query, qa.UserID, qa.Username, qa.Question, qa.Answer).Scan(&newID)
+    if err != nil {
+        return 0, fmt.Errorf("insert qa: %w", err)
+    }
+    return newID, nil
+}
+
+func mainQA() {
+    flag.Parse()
+    ctx := context.Background()
+
+    if *connString == "" {
+        log.Fatal("need -dbconn")
+    }
+
+    db, err := sql.Open("postgres", *connString)
+    if err != nil {
+        log.Fatalf("open database: %v", err)
+    }
+    defer db.Close()
+
+    store := NewQAStore(db)
+
+    // 示例：读取 user_id=101 的最新 QA
+    results, err := store.GetLatestQA(ctx, int64Ptr(101))
+    if err != nil {
+        log.Fatalf("get latest QA: %v", err)
+    }
+    for _, qa := range results {
+        fmt.Printf("ID: %d, CreatedAt: %v, UserID: %v, Username: %v, Question: %v, Answer: %v\n",
+            qa.ID, qa.CreatedAt, derefInt64(qa.UserID), derefString(qa.Username), derefString(qa.Question), derefString(qa.Answer))
+    }
+
+    // 示例：插入新 QA
+    newQA := QA{
+        UserID:   int64Ptr(101),
+        Username: stringPtr("alice"),
+        Question: stringPtr("What is AI?"),
+        Answer:   stringPtr("AI is..."),
+    }
+    newID, err := store.WriteQA(ctx, newQA)
+    if err != nil {
+        log.Fatalf("write QA: %v", err)
+    }
+    fmt.Printf("Inserted QA with ID: %d\n", newID)
+
+    // 示例：更新 QA
+    updateQA := QA{
+        ID:       newID,
+        UserID:   int64Ptr(101),
+        Username: stringPtr("alice_updated"),
+        Question: stringPtr("What is NLP?"),
+        Answer:   stringPtr("NLP is..."),
+    }
+    updatedID, err := store.WriteQA(ctx, updateQA)
+    if err != nil {
+        log.Fatalf("update QA: %v", err)
+    }
+    fmt.Printf("Updated QA with ID: %d\n", updatedID)
+}
+
+// 辅助函数：处理指针类型的空值
+func int64Ptr(i int64) *int64 {
+    return &i
+}
+
+func stringPtr(s string) *string {
+    return &s
+}
+
+func derefInt64(p *int64) interface{} {
+    if p == nil {
+        return nil
+    }
+    return *p
+}
+
+func derefString(p *string) interface{} {
+    if p == nil {
+        return nil
+    }
+    return *p
+}
\ No newline at end of file