dbcli-db-ddl

name	dbcli-db-ddl
description	Execute DDL (Data Definition Language) statements - CREATE, ALTER, DROP tables, indexes, views on 30+ databases using DbCli. CRITICAL - requires mandatory backup before DROP/ALTER operations. Use when user needs to create schema, modify structure, or drop database objects.
license	MIT
compatibility	Requires DbCli CLI tool (based on .NET 10 and SqlSugar). Supports Windows, Linux, macOS.
metadata	{"tool":"dbcli","version":"1.0.0","category":"database","safety-level":"critical-requires-backup","supported-databases":"30+"}
allowed-tools	dbcli

Command Style (Use PATH)

All examples use the plain command name dbcli (no directory prefix). Ensure dbcli is on PATH instead of hardcoding paths like .\.claude\skills\dbcli\dbcli.exe.

DbCli Database DDL Skill

Execute Data Definition Language (DDL) operations - CREATE, ALTER, DROP tables, indexes, and views.

⚠️ CRITICAL SAFETY REQUIREMENT

MANDATORY BACKUPS BEFORE DROP/ALTER OPERATIONS

• DROP TABLE: Export table data + create table copy
• ALTER TABLE: Export table schema + data
• DROP INDEX/VIEW: Document structure before dropping

When to Use This Skill

• User wants to create tables, indexes, or views
• User needs to modify table structure (add/drop columns, change types)
• User wants to drop tables, indexes, or views
• User mentions CREATE, ALTER, DROP, schema, structure, or database design
• Never DROP/ALTER without backups

Command Syntax

DBCLI_CONNECTION="CONNECTION_STRING" DBCLI_DBTYPE="DATABASE_TYPE" dbcli ddl "DDL_STATEMENT"

Global Options

• Environment variable DBCLI_CONNECTION: Database connection string (required)
• Environment variable DBCLI_DBTYPE: Database type (default: sqlite)
• --config <path>: Config file path (e.g. appsettings.json) (optional)

Subcommand Options

• -F, --file: Execute DDL from file

Notes:

• SQL Server supports GO batch separators in DDL scripts (use -F and keep GO on its own line).

CREATE Operations (Safe - No Backup Required)

Create Table

# SQLite - Basic table
DBCLI_CONNECTION="Data Source=app.db" dbcli ddl "CREATE TABLE Users (Id INTEGER PRIMARY KEY AUTOINCREMENT, Name TEXT NOT NULL, Email TEXT UNIQUE, CreatedAt TIMESTAMP DEFAULT CURRENT_TIMESTAMP)"

# SQL Server
DBCLI_CONNECTION="Server=localhost;Database=mydb;Trusted_Connection=True" DBCLI_DBTYPE="sqlserver" dbcli ddl "CREATE TABLE Users (Id INT PRIMARY KEY IDENTITY(1,1), Name NVARCHAR(100) NOT NULL, Email NVARCHAR(255) UNIQUE, CreatedAt DATETIME DEFAULT GETDATE())"

# MySQL
DBCLI_CONNECTION="Server=localhost;Database=mydb;Uid=root;Pwd=xxxxxxxxxx" DBCLI_DBTYPE="mysql" dbcli ddl "CREATE TABLE Users (Id INT PRIMARY KEY AUTO_INCREMENT, Name VARCHAR(100) NOT NULL, Email VARCHAR(255) UNIQUE, CreatedAt TIMESTAMP DEFAULT CURRENT_TIMESTAMP)"

# PostgreSQL
DBCLI_CONNECTION="Host=localhost;Database=mydb;Username=postgres;Password=xxxxxxxxxx" DBCLI_DBTYPE="postgresql" dbcli ddl "CREATE TABLE Users (Id SERIAL PRIMARY KEY, Name VARCHAR(100) NOT NULL, Email VARCHAR(255) UNIQUE, CreatedAt TIMESTAMP DEFAULT CURRENT_TIMESTAMP)"

Create Table with Foreign Key

DBCLI_CONNECTION="Data Source=app.db" dbcli ddl "CREATE TABLE Orders (Id INTEGER PRIMARY KEY AUTOINCREMENT, UserId INTEGER NOT NULL, Total REAL NOT NULL, OrderDate TIMESTAMP DEFAULT CURRENT_TIMESTAMP, FOREIGN KEY (UserId) REFERENCES Users(Id))"

Create Table from Query (Backup/Copy)

# Create backup table
DBCLI_CONNECTION="Data Source=app.db" dbcli ddl "CREATE TABLE Users_backup AS SELECT * FROM Users"

# Create filtered copy
DBCLI_CONNECTION="Data Source=app.db" dbcli ddl "CREATE TABLE ActiveUsers AS SELECT * FROM Users WHERE active = 1"

Create Table if Not Exists

DBCLI_CONNECTION="Data Source=app.db" dbcli ddl "CREATE TABLE IF NOT EXISTS Settings (Key TEXT PRIMARY KEY, Value TEXT)"

Create Index

# Single column index
DBCLI_CONNECTION="Data Source=app.db" dbcli ddl "CREATE INDEX idx_users_email ON Users(Email)"

# Multi-column index
DBCLI_CONNECTION="Data Source=app.db" dbcli ddl "CREATE INDEX idx_orders_user_date ON Orders(UserId, OrderDate)"

# Unique index
DBCLI_CONNECTION="Data Source=app.db" dbcli ddl "CREATE UNIQUE INDEX idx_users_username ON Users(Username)"

Create View

# Simple view
DBCLI_CONNECTION="Data Source=app.db" dbcli ddl "CREATE VIEW ActiveUsers AS SELECT Id, Name, Email FROM Users WHERE active = 1"

# Complex view with JOIN
DBCLI_CONNECTION="Data Source=app.db" dbcli ddl "CREATE VIEW UserOrders AS SELECT u.Name, o.Id as OrderId, o.Total, o.OrderDate FROM Users u JOIN Orders o ON u.Id = o.UserId"

DROP Operations (DANGEROUS - Requires Backup)

Safe DROP TABLE Workflow

TIMESTAMP=$(date +%Y%m%d_%H%M%S)

# STEP 1: Export table schema (for reference)
DBCLI_CONNECTION="Data Source=app.db" dbcli -f table columns OldTable > OldTable_schema_${TIMESTAMP}.txt

# STEP 2: Export table data (SQL format)
DBCLI_CONNECTION="Data Source=app.db" dbcli export OldTable > OldTable_backup_${TIMESTAMP}.sql

# STEP 3: Create table copy (fastest recovery)
DBCLI_CONNECTION="Data Source=app.db" dbcli query "CREATE TABLE OldTable_copy_${TIMESTAMP} AS SELECT * FROM OldTable"

# STEP 4: Verify backup
DBCLI_CONNECTION="Data Source=app.db" dbcli query "SELECT COUNT(*) FROM OldTable"
DBCLI_CONNECTION="Data Source=app.db" dbcli query "SELECT COUNT(*) FROM OldTable_copy_${TIMESTAMP}"

# STEP 5: Drop table
DBCLI_CONNECTION="Data Source=app.db" dbcli ddl "DROP TABLE IF EXISTS OldTable"

echo "Table dropped. Backups: OldTable_backup_${TIMESTAMP}.sql, OldTable_copy_${TIMESTAMP}"

Safe DROP INDEX

# Document index before dropping
DBCLI_CONNECTION="Data Source=app.db" dbcli query "SELECT sql FROM sqlite_master WHERE type='index' AND name='idx_old_index'" > idx_old_index_definition.sql

# Drop index
DBCLI_CONNECTION="Data Source=app.db" dbcli ddl "DROP INDEX IF EXISTS idx_old_index"

Safe DROP VIEW

# Export view definition
DBCLI_CONNECTION="Data Source=app.db" dbcli query "SELECT sql FROM sqlite_master WHERE type='view' AND name='OldView'" > OldView_definition.sql

# Drop view
DBCLI_CONNECTION="Data Source=app.db" dbcli ddl "DROP VIEW IF EXISTS OldView"

ALTER Operations (CRITICAL - Requires Backup)

Safe ALTER TABLE Workflow

TIMESTAMP=$(date +%Y%m%d_%H%M%S)

# STEP 1: Full table backup (data + schema)
DBCLI_CONNECTION="Data Source=app.db" dbcli export Users > Users_backup_${TIMESTAMP}.sql
DBCLI_CONNECTION="Data Source=app.db" dbcli query "CREATE TABLE Users_copy_${TIMESTAMP} AS SELECT * FROM Users"

# STEP 2: Verify backup
DBCLI_CONNECTION="Data Source=app.db" dbcli query "SELECT COUNT(*) FROM Users"
DBCLI_CONNECTION="Data Source=app.db" dbcli query "SELECT COUNT(*) FROM Users_copy_${TIMESTAMP}"

# STEP 3: Execute ALTER
DBCLI_CONNECTION="Data Source=app.db" dbcli ddl "ALTER TABLE Users ADD COLUMN PhoneNumber TEXT"

# STEP 4: Verify structure
DBCLI_CONNECTION="Data Source=app.db" dbcli -f table columns Users

ALTER TABLE - Add Column

# Backup first
TIMESTAMP=$(date +%Y%m%d_%H%M%S)
DBCLI_CONNECTION="Data Source=app.db" dbcli export Users > Users_backup_${TIMESTAMP}.sql

# Add column
DBCLI_CONNECTION="Data Source=app.db" dbcli ddl "ALTER TABLE Users ADD COLUMN Age INTEGER"

# Add column with default
DBCLI_CONNECTION="Data Source=app.db" dbcli ddl "ALTER TABLE Users ADD COLUMN Status TEXT DEFAULT 'active'"

ALTER TABLE - Drop Column

# CRITICAL: Full backup required
TIMESTAMP=$(date +%Y%m%d_%H%M%S)
DBCLI_CONNECTION="Data Source=app.db" dbcli export Users > Users_backup_${TIMESTAMP}.sql
DBCLI_CONNECTION="Data Source=app.db" dbcli query "CREATE TABLE Users_copy_${TIMESTAMP} AS SELECT * FROM Users"

# Drop column (SQL Server syntax)
DBCLI_CONNECTION="Server=localhost;Database=mydb;Trusted_Connection=True" DBCLI_DBTYPE="sqlserver" dbcli ddl "ALTER TABLE Users DROP COLUMN TempColumn"

ALTER TABLE - Rename Table

# Backup first
TIMESTAMP=$(date +%Y%m%d_%H%M%S)
DBCLI_CONNECTION="Data Source=app.db" dbcli export OldName > OldName_backup_${TIMESTAMP}.sql

# Rename (SQLite syntax)
DBCLI_CONNECTION="Data Source=app.db" dbcli ddl "ALTER TABLE OldName RENAME TO NewName"

# Rename (SQL Server syntax)
DBCLI_CONNECTION="Server=localhost;Database=mydb;Trusted_Connection=True" DBCLI_DBTYPE="sqlserver" dbcli ddl "EXEC sp_rename 'OldName', 'NewName'"

ALTER TABLE - Rename Column

# Backup first
TIMESTAMP=$(date +%Y%m%d_%H%M%S)
DBCLI_CONNECTION="Data Source=app.db" dbcli export Users > Users_backup_${TIMESTAMP}.sql

# Rename column (SQLite 3.25+)
DBCLI_CONNECTION="Data Source=app.db" dbcli ddl "ALTER TABLE Users RENAME COLUMN OldColumnName TO NewColumnName"

# SQL Server
DBCLI_CONNECTION="Server=localhost;Database=mydb;Trusted_Connection=True" DBCLI_DBTYPE="sqlserver" dbcli ddl "EXEC sp_rename 'Users.OldColumnName', 'NewColumnName', 'COLUMN'"

DDL from File

Execute Schema File

# Create schema.sql
cat > schema.sql <<EOF
CREATE TABLE Users (
    Id INTEGER PRIMARY KEY AUTOINCREMENT,
    Name TEXT NOT NULL,
    Email TEXT UNIQUE,
    CreatedAt TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

CREATE TABLE Orders (
    Id INTEGER PRIMARY KEY AUTOINCREMENT,
    UserId INTEGER NOT NULL,
    Total REAL NOT NULL,
    OrderDate TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    FOREIGN KEY (UserId) REFERENCES Users(Id)
);

CREATE INDEX idx_users_email ON Users(Email);
CREATE INDEX idx_orders_user ON Orders(UserId);
EOF

# Execute schema
DBCLI_CONNECTION="Data Source=app.db" dbcli ddl -F schema.sql

Migration Scripts

# migrations/001_create_users.sql
DBCLI_CONNECTION="Data Source=app.db" dbcli ddl -F migrations/001_create_users.sql

# migrations/002_add_orders.sql
DBCLI_CONNECTION="Data Source=app.db" dbcli ddl -F migrations/002_add_orders.sql

# migrations/003_add_indexes.sql
DBCLI_CONNECTION="Data Source=app.db" dbcli ddl -F migrations/003_add_indexes.sql

DaMeng

# Create table
DBCLI_CONNECTION="Server=localhost;User Id=SYSDBA;PWD=xxxxxxxxxx;DATABASE=mydb" DBCLI_DBTYPE="dm" dbcli ddl "CREATE TABLE dm_test (id INT PRIMARY KEY, name VARCHAR(100), create_time TIMESTAMP)"

# Create index
DBCLI_CONNECTION="Server=localhost;User Id=SYSDBA;PWD=xxxxxxxxxx;DATABASE=mydb" DBCLI_DBTYPE="dm" dbcli ddl "CREATE INDEX idx_dm_test_name ON dm_test(name)"

# Create view
DBCLI_CONNECTION="Server=localhost;User Id=SYSDBA;PWD=xxxxxxxxxx;DATABASE=mydb" DBCLI_DBTYPE="dm" dbcli ddl "CREATE VIEW v_dm_test AS SELECT id, name FROM dm_test WHERE id > 0"

GaussDB

# Create table with sequence
DBCLI_CONNECTION="Host=localhost;Port=8000;Database=mydb;Username=gaussdb;Password=xxxxxxxxxx" DBCLI_DBTYPE="gaussdb" dbcli ddl "CREATE TABLE gauss_test (id SERIAL PRIMARY KEY, name VARCHAR(100), amount DECIMAL(10,2))"

# Create index
DBCLI_CONNECTION="Host=localhost;Port=8000;Database=mydb;Username=gaussdb;Password=xxxxxxxxxx" DBCLI_DBTYPE="gaussdb" dbcli ddl "CREATE INDEX idx_gauss_test_name ON gauss_test(name)"

# Create function (PL/pgSQL)
DBCLI_CONNECTION="Host=localhost;Port=8000;Database=mydb;Username=gaussdb;Password=xxxxxxxxxx" DBCLI_DBTYPE="gaussdb" dbcli ddl "CREATE OR REPLACE FUNCTION get_total() RETURNS DECIMAL AS \$\$ BEGIN RETURN (SELECT SUM(amount) FROM gauss_test); END; \$\$ LANGUAGE plpgsql"

KingbaseES (人大金仓)

# Create table
DBCLI_CONNECTION="Server=localhost;Port=54321;UID=system;PWD=xxxxxxxxxx;database=mydb" DBCLI_DBTYPE="kdbndp" dbcli ddl "CREATE TABLE kingbase_test (id SERIAL PRIMARY KEY, name VARCHAR(100), price NUMERIC(10,2))"

# Create view
DBCLI_CONNECTION="Server=localhost;Port=54321;UID=system;PWD=xxxxxxxxxx;database=mydb" DBCLI_DBTYPE="kdbndp" dbcli ddl "CREATE VIEW v_kingbase_active AS SELECT * FROM kingbase_test WHERE status = 1"

Advanced DDL

Composite Primary Key

DBCLI_CONNECTION="Data Source=app.db" dbcli ddl "CREATE TABLE UserRoles (UserId INTEGER NOT NULL, RoleId INTEGER NOT NULL, AssignedAt TIMESTAMP DEFAULT CURRENT_TIMESTAMP, PRIMARY KEY (UserId, RoleId))"

Check Constraints

DBCLI_CONNECTION="Data Source=app.db" dbcli ddl "CREATE TABLE Products (Id INTEGER PRIMARY KEY, Name TEXT NOT NULL, Price REAL CHECK(Price > 0), Stock INTEGER CHECK(Stock >= 0))"

Triggers (SQLite)

DBCLI_CONNECTION="Data Source=app.db" dbcli ddl "CREATE TRIGGER update_timestamp AFTER UPDATE ON Users BEGIN UPDATE Users SET UpdatedAt = datetime('now') WHERE Id = NEW.Id; END"

Partial Index

DBCLI_CONNECTION="Data Source=app.db" dbcli ddl "CREATE INDEX idx_active_users ON Users(Email) WHERE active = 1"

Backup Recovery for DDL

Recover Dropped Table

# From table copy
DBCLI_CONNECTION="Data Source=app.db" dbcli ddl "CREATE TABLE Users AS SELECT * FROM Users_copy_20250127_143022"

# From SQL export
DBCLI_CONNECTION="Data Source=app.db" dbcli exec -F Users_backup_20250127_143022.sql

Recover Dropped Index

# Re-create from saved definition
DBCLI_CONNECTION="Data Source=app.db" dbcli ddl -F idx_users_email_definition.sql

Rollback ALTER TABLE

# Drop altered table
DBCLI_CONNECTION="Data Source=app.db" dbcli ddl "DROP TABLE Users"

# Restore from backup
DBCLI_CONNECTION="Data Source=app.db" dbcli ddl "CREATE TABLE Users AS SELECT * FROM Users_copy_20250127_143022"

Schema Verification

Check Table Exists

# SQLite
DBCLI_CONNECTION="Data Source=app.db" dbcli query "SELECT name FROM sqlite_master WHERE type='table' AND name='Users'"

# SQL Server
DBCLI_CONNECTION="Server=localhost;Database=mydb;Trusted_Connection=True" DBCLI_DBTYPE="sqlserver" dbcli query "SELECT TABLE_NAME FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME = 'Users'"

Check Column Exists

# SQLite
DBCLI_CONNECTION="Data Source=app.db" dbcli query "PRAGMA table_info(Users)"

# SQL Server
DBCLI_CONNECTION="Server=localhost;Database=mydb;Trusted_Connection=True" DBCLI_DBTYPE="sqlserver" dbcli query "SELECT COLUMN_NAME FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = 'Users' AND COLUMN_NAME = 'Email'"

Check Index Exists

# SQLite
DBCLI_CONNECTION="Data Source=app.db" dbcli query "SELECT name FROM sqlite_master WHERE type='index' AND tbl_name='Users' AND name='idx_users_email'"

Common Patterns

Idempotent DDL (Safe Re-run)

# Drop if exists, then create
DBCLI_CONNECTION="Data Source=app.db" dbcli ddl "DROP TABLE IF EXISTS TempTable"
DBCLI_CONNECTION="Data Source=app.db" dbcli ddl "CREATE TABLE TempTable (Id INTEGER PRIMARY KEY, Data TEXT)"

# Create if not exists
DBCLI_CONNECTION="Data Source=app.db" dbcli ddl "CREATE TABLE IF NOT EXISTS Settings (Key TEXT PRIMARY KEY, Value TEXT)"

Database Initialization

#!/bin/bash
# init_db.sh

CONNECTION="Data Source=app.db"

# Create tables
DBCLI_CONNECTION="$CONNECTION" dbcli ddl -F schema/001_users.sql
DBCLI_CONNECTION="$CONNECTION" dbcli ddl -F schema/002_orders.sql
DBCLI_CONNECTION="$CONNECTION" dbcli ddl -F schema/003_products.sql

# Create indexes
DBCLI_CONNECTION="$CONNECTION" dbcli ddl -F schema/004_indexes.sql

# Create views
DBCLI_CONNECTION="$CONNECTION" dbcli ddl -F schema/005_views.sql

echo "Database initialized"

Schema Migration

#!/bin/bash
# migrate.sh

CONNECTION="Data Source=app.db"
BACKUP_DIR="backups"
TIMESTAMP=$(date +%Y%m%d_%H%M%S)

# Backup entire database
cp app.db "${BACKUP_DIR}/app_${TIMESTAMP}.db"

# Run migrations
for migration in migrations/*.sql; do
    echo "Running $migration..."
    DBCLI_CONNECTION="$CONNECTION" dbcli ddl -F "$migration"
    if [ $? -ne 0 ]; then
        echo "Migration failed: $migration"
        echo "Restoring from backup..."
        cp "${BACKUP_DIR}/app_${TIMESTAMP}.db" app.db
        exit 1
    fi
done

echo "All migrations completed successfully"

Security Best Practices

1. Always backup before DROP/ALTER - Cannot emphasize enough
2. Test DDL on backup database first
3. Use transactions for multiple DDL operations when supported
4. Document schema changes with timestamps and reasons
5. Version control all DDL scripts
6. Limit DDL permissions to admin users only
7. Review constraints before adding (can block future inserts)