将Excel导出为SQL语句

需求说明：公司做项目前进行需求分析，确定表结构后需要建表，如果照着表格去敲，那就太麻烦了，所以想到了自动生成SQL语句。

思路大概就是：解析Excel，拼接SQL语句，输出SQL文件。

第三方jar包：POI（解析Excel）

先建立一个maven项目。

pom依赖：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.transition</groupId>
    <artifactId>excel-to-sql</artifactId>
    <version>1.0-SNAPSHOT</version>

    <dependencies>
        <!-- https://mvnrepository.com/artifact/org.apache.poi/poi -->
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi</artifactId>
            <version>3.17</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.apache.poi/poi-ooxml -->
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml</artifactId>
            <version>3.17</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.apache.poi/poi-ooxml-schemas -->
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml-schemas</artifactId>
            <version>3.17</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.apache.xmlbeans/xmlbeans -->
        <dependency>
            <groupId>org.apache.xmlbeans</groupId>
            <artifactId>xmlbeans</artifactId>
            <version>2.6.0</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/dom4j/dom4j -->
        <dependency>
            <groupId>dom4j</groupId>
            <artifactId>dom4j</artifactId>
            <version>1.6.1</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <!-- 编译插件 -->
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.7.0</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

目录结构

Keys.Java

package com.transition.core.common;

public class Keys {
    public static final String TABLE_PRE = "DROP TABLE IF EXISTS ";
    public static final String TABLE_SUFF = "ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT=";
    public static final String C_T = "CREATE TABLE ";
    public static final String N_N = " NOT NULL ";
    public static final String A_I = "AUTO_INCREMENT";
    public static final String P_K = "PRIMARY KEY ";
    public static final String F_K = " FOREIGN KEY ";
    public static final String COMMENT = " COMMENT ";
    public static final String DEFAULT = " DEFAULT ";

}

DataTable.Java

package com.transition.core.entity;

import java.util.ArrayList;
import java.util.List;

/**
 * 数据库表
 */
public class DataTable {

    private String tableName;   // 数据库表名
    private String comment;     //数据库注释
    private List<TableField> fields = new ArrayList<>();

    public DataTable() {
    }

    public DataTable(String tableName, String comment) {
        this.tableName = tableName;
        this.comment = comment;
    }

    public String getTableName() {
        return tableName;
    }

    public void setTableName(String tableName) {
        this.tableName = tableName;
    }

    public String getComment() {
        return comment;
    }

    public void setComment(String comment) {
        this.comment = comment;
    }

    public List<TableField> getFields() {
        return fields;
    }

    public void setFields(List<TableField> fields) {
        this.fields = fields;
    }

    @Override
    public String toString() {
        return "DataTable{" +
                "tableName='" + tableName + '\'' +
                ", comment='" + comment + '\'' +
                ", fields=" + fields +
                '}';
    }
}

TableField.Java

package com.transition.core.entity;

/**
 * 表字段
 */
public class TableField {

    private String fieldName;   // 字段名
    private String fieldType;   // 字段类型
    private String isNull;      // 是否为空
    private String defaultValue;// 默认值
    private String comment;     // 注释

    public TableField() {
    }

    public TableField(String fieldName, String fieldType, String isNull, String defaultValue, String comment) {
        this.fieldName = fieldName;
        this.fieldType = fieldType;
        this.isNull = isNull;
        this.defaultValue = defaultValue;
        this.comment = comment;
    }

    public String getFieldName() {
        return fieldName;
    }

    public void setFieldName(String fieldName) {
        this.fieldName = fieldName;
    }

    public String getFieldType() {
        return fieldType;
    }

    public void setFieldType(String fieldType) {
        this.fieldType = fieldType;
    }

    public String getIsNull() {
        return isNull;
    }

    public void setIsNull(String isNull) {
        this.isNull = isNull;
    }

    public String getDefaultValue() {
        return defaultValue;
    }

    public void setDefaultValue(String defaultValue) {
        this.defaultValue = defaultValue;
    }

    public String getComment() {
        return comment;
    }

    public void setComment(String comment) {
        this.comment = comment;
    }

    @Override
    public String toString() {
        return "TableField{" +
                "fieldName='" + fieldName + '\'' +
                ", fieldType='" + fieldType + '\'' +
                ", isNull='" + isNull + '\'' +
                ", defaultValue='" + defaultValue + '\'' +
                ", comment='" + comment + '\'' +
                '}';
    }
}

Core

package com.transition.core;

import com.transition.core.common.Keys;
import com.transition.core.entity.DataTable;
import com.transition.core.entity.TableField;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.CellType;
import org.apache.poi.xssf.usermodel.XSSFRow;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

import java.io.*;
import java.util.ArrayList;
import java.util.List;

public class Core {

    private static int tableNum = 0;
    private static int sentry = -1;  // 哨兵

    public static List<DataTable> readXlsx(String path){
        List<DataTable> list = new ArrayList<>();
        System.out.println("读取...");
        InputStream in = null;
        try {
            in = new FileInputStream(path);
            XSSFWorkbook xss = new XSSFWorkbook(in);

            for(int i = 0; i < xss.getNumberOfSheets(); i++){
                XSSFSheet sheet = xss.getSheetAt(i);
                if(sheet == null)
                    continue;

                for(int r = 0; r <= sheet.getLastRowNum(); r++){
                    XSSFRow row = sheet.getRow(r);
                    if(row != null){
                        // 如果哨兵等于0，代表这一行是不需要读取的。continue之后自减1
                        if (sentry-- == 0){
                            continue;
                        }
                        /*
                            _NONE(-1),
                            NUMERIC(0),
                            STRING(1),
                            FORMULA(2),
                            BLANK(3),
                            BOOLEAN(4),
                            ERROR(5);
                         */
                        CellType cellType2 = row.getCell(2).getCellTypeEnum();
                        CellType cellType3 = row.getCell(3).getCellTypeEnum();
                        CellType cellType4 = row.getCell(4).getCellTypeEnum();
                        if (cellType2 == CellType.BLANK && cellType3 == CellType.BLANK && cellType4 == CellType.BLANK){
                            ++tableNum;
                            sentry = 0;

                            String name = row.getCell(0).getStringCellValue().toLowerCase();
                            String comment = row.getCell(1).getStringCellValue();

                            list.add(new DataTable(name, comment));
                            System.out.println("----------------------Table-------------------");
                            System.out.println("表名：" + name + ",注释：" + comment);
                            continue;
                        }

                        if(cellType3 == CellType.NUMERIC)
                            list.get(list.size()-1).getFields().add(new TableField(row.getCell(0).getStringCellValue(),
                                    row.getCell(1).getStringCellValue(),
                                    row.getCell(2).getStringCellValue(),
                                    Math.round(row.getCell(3).getNumericCellValue())+"",
                                    row.getCell(4).getStringCellValue()));
                        else
                            list.get(list.size()-1).getFields().add(new TableField(row.getCell(0).getStringCellValue(),
                                    row.getCell(1).getStringCellValue(),
                                    row.getCell(2).getStringCellValue(),
                                    row.getCell(3).getStringCellValue(),
                                    row.getCell(4).getStringCellValue()));

                    }

                }

            }
            in.close();

        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return list;
    }

    public static void exportToSQL(List<DataTable> list, String sqlPath) throws IOException {
        final List<String> sql = new ArrayList<>();
        list.forEach(e -> {
            sentry = 1;
            StringBuilder sb = new StringBuilder();
            sb.append(Keys.TABLE_PRE + "`" + e.getTableName() + "`;\n");
            sb.append(Keys.C_T + "`" + e.getTableName() + "` (\n");
            e.getFields().forEach(c -> {
                // 只有主键有自增
                if (sentry == 1){
                    sb.append("`" + c.getFieldName().toLowerCase() + "` " + c.getFieldType().toLowerCase() + Keys.N_N + Keys.A_I + Keys.COMMENT + "'" + c.getComment() + "',\n");
                    sentry = 0;
                }else {
                    // 如果无默认值
                    if (c.getDefaultValue() == null || c.getDefaultValue().equals("")){
                        // 如果不为空，或者无标志，一律按照不为空处理
                        if ("N".equals(c.getIsNull()) || "".equals(c.getIsNull()) || c.getIsNull() == null)
                            sb.append("`" + c.getFieldName().toLowerCase() + "` " + c.getFieldType().toLowerCase() + Keys.N_N + Keys.COMMENT + "'" + c.getComment() + "',\n");
                        else
                            sb.append("`" + c.getFieldName().toLowerCase() + "` " + c.getFieldType().toLowerCase() + Keys.COMMENT + "'" + c.getComment() + "',\n");
                    } else{
                        // 如果不为空，或者无标志，一律按照不为空处理
                        if ("N".equals(c.getIsNull()) || "".equals(c.getIsNull()) || c.getIsNull() == null)
                            sb.append("`" + c.getFieldName().toLowerCase() + "` " + c.getFieldType().toLowerCase() + Keys.N_N + Keys.DEFAULT + "'" + c.getDefaultValue() + "'" + Keys.COMMENT + "'" + c.getComment() + "',\n");
                        else
                            sb.append("`" + c.getFieldName().toLowerCase() + "` " + c.getFieldType().toLowerCase() + Keys.DEFAULT + "'" + c.getDefaultValue() + "'" + Keys.COMMENT + "'" + c.getComment() + "',\n");
                    }

                }

            });
            sb.append(Keys.P_K + "(`" + e.getFields().get(0).getFieldName().toLowerCase() + "`)\n" +
                    ") " + Keys.TABLE_SUFF + "'" + e.getComment() + "';\n\n");
            System.out.println(sb.toString());
            sql.add(sb.toString());
        });

        File file = new File(sqlPath);
        FileOutputStream out = new FileOutputStream(file);
        sql.forEach(s -> {
            try {
                out.write(s.getBytes());
            } catch (IOException e) {
                e.printStackTrace();
            }
        });
        out.close();
    }

    public static int getTableNum() {
        return tableNum;
    }
}

RunApplication

package com.transition.core;

import com.transition.core.entity.DataTable;

import java.io.IOException;
import java.util.List;

public class RunApplication {

    public static void main(String[] args) throws IOException {
        List<DataTable> tables = Core.readXlsx("table2.xlsx");
        // tables.forEach(e -> System.out.println(e));
        Core.exportToSQL(tables,"test.sql");
        System.out.println("TableNumber : " + Core.getTableNum());
    }
}

我要读取table2.xlsx，输出到test.sql

运行，输出结果：

查看sql文件

在Navicat里面运行这个sql文件

可以看到，字段名全部是小写，类型，长度，字段注释都正确设置，是否为空也符合要求。

不过有个事情：如果你要添加外键依赖，触发器之类的要自己手动去配置。另外，这个代码有点特定为这种格式的表格，如果你不是这种结果的表格，很可能不成功。

如果你不会改就叫我好了

不过，如果你有很多表的话，帮你生成已经节省很多时间了，还要啥自行车啊